You are given a text that consists of multiple sentences. Your task is to perform abstractive summarization on this text. Use your understanding of the content to express the main ideas and crucial details in a shorter, coherent, and natural sounding text. 
Text: Three months ago we said that 2021 was shaping up to be a great year for United Rentals, and that's still very much the case.
Our operating environment continues to recover.
Our customers are increasingly optimistic about their prospects and our company is continuing to lean into growth from a position of strength as a premium provider and our industry's largest one-stop shop, with the supply leader in the demand environment, and we've leveraged that to deliver another consecutive quarter of strong results.
The big themes of the second quarter are strong growth in line with our expectations and robust free cash flow, either after the step up in our capex, positive industry indicators, including a strong used-equipment market, where pricing was up 7% year-over-year.
The expansion of our go-to-market platform through M&A and cold starts.
This is timed to the broad based recovery in demand and our focus on operational discipline, as we manage the increase in both volume and capacity, while driving fleet productivity of nearly 18%.
Another key takeaway our safety performance and I'm very proud of the team for holding the line on safety with another recordable rate below 1, while at the same time managing a robust busy season and on-boarding our acquired locations.
This includes General Finance, which we acquired at the end of May.
As you know, this was both a strategic and financial move designed to build on our strength.
The acquisition expanded our growth capacity and gave us a leading position in the rental market for mobile storage and office solutions.
The integration is going well.
And while we still have more work to do, we're moving steadily through our playbook.
As you saw in our release, we raised our outlook to include the expected impact of General Finance and other M&A we closed since the first quarter.
It also includes some additional investments we plan to make in capex that will serve us beyond 2021.
This outlook follows the higher guidance we issued in April when we raised every range compared to our initial guidance.
So as you can see, we're tenacious about pursuing profitable growth and the investments we're making will still have a positive impact on our immediate performance as well as future years.
And before Jess gets into the numbers, I want to spend a few minutes on our operating landscape.
Almost all of the challenges of 2020 have right of themselves.
We have a better line of sight and so to our customer.
When we surveyed our customers at the end of June, the results showed that over 60% of our customers expect to grow their business over the coming 12 months, which is a post-pandemic high.
And notably, only 3% saw a decline coming over the same period.
Customer optimism is a great barometer and the trends we see in the field support their view.
2021 is a pivotal year for us.
It confirms our return to growth, including our 19% rental revenue growth in the second quarter.
I'll point to some of the drivers of that growth, starting with geography.
The rebound in our end markets continues to be broadly positive with all geographic regions reporting year-over-year growth in rental revenue.
Our Specialty segment generated another strong performance with rental revenue topping 25% year-over-year, including same-store growth of over 19%.
And importantly, we grew each major line of business by double digits, which underscores the broadness of the demand.
For years now, our investment in building out our specialty network has been a key to our strategic position.
These services differentiate our offering to customers and add resilience to our results throughout the cycle and this is true of cold starts as well as M&A.
This year, we've opened 19 new specialty branches in the first six months, which puts us well on our way to our goal of 30 by year-end.
We're also investing in growth in our General Rental segment, where the big drivers are non-res construction and plant maintenance.
Both areas a continuing to gain traction and most of our end markets are trending up.
Verticals like chemical process, food and beverage, metals and mining, and healthcare all showing solid growth.
And while the energy sector remains a laggard, it was up year-over-year for the first time in eight quarters.
We also have customers in verticals that are less mainstream, like entertainment, where demand for our equipment on movie sets and events more than doubled in the quarter.
And while it's a relatively small part of the revenue, it's a good sign to see it come back.
I also want to give you some color on project types.
There are two takeaways, the diversity of the projects in Q2 and the fact that each region contributed to growth in its own way.
The recovery has taking root across geographies and verticals on both coasts, with solid activity in heavy manufacturing, corporate campuses, schools and transmission lines.
In this quarter, we're also seeing project starts in power transit and technology.
These job sites are using our General Rental equipment and our trench safety and power solutions.
And fluid solutions has seen a rebound in chemical processing and sewer [Indecipherable] as well as mining.
These are just a few of the favorable dynamics in a very promising up cycle.
And I want to put that in context.
2020 was about the temporary loss of market opportunity, particularly in the second quarter.
Now, the pendulum is swinging back.
And 2021 is about locking in that opportunity within the framework of our strategy and our team is managing that extremely well.
One proof point is our financial performance and the confidence we have in our guidance.
Another is our willingness to lean into growth today to create outsized value tomorrow.
And it's about more than capex and cold starts.
We're constantly exploring new ways to capture growth by testing new products in the field, developing new sales pipelines and forging digital connections with customers.
And finally, the most important proof point is the quality of our team.
You could see that reflected our safety record and our strong culture.
And here's the thing to remember about 2021.
This is still the early innings of the recovery.
We're committed to capitalize on more and more demand as the opportunity unfolds.
We see a long runway ahead to drive growth, create value and deliver shareholder returns.
Over to you, Jess.
When we increased our 2021 guidance back in April, we expected a strong second quarter supported by the momentum we were seeing to start the year.
We're pleased to see that play out as anticipated with the second quarter results.
And importantly, we're also pleased to see the momentum accelerate in our core business and support another raise to our guidance for the year.
We've also added the impact from our acquisitions, notably the General Finance deals.
And I'll give a little bit more color on our guidance in a few minutes, but let's start now with the results for the second quarter.
Rental revenue for the second quarter was $1.95 billion, that's an increase of $309 million or 19%.
If I exclude the impact of acquisitions on that number, rental revenue from the core business grew a healthy 16% year-over-year.
Within rental revenue, OER increased $231 million or 16.5%.
The biggest driver in that change with fleet productivity, which was up 17.8% or $250 million, that's primarily due to stronger fleet absorption on higher volumes in part as we comp the COVID-impacted second quarter last year.
Our average fleet size was up 0.2% or a $3 million tailwind to revenue and rounding out OER, the inflation impact of 1.5% cost us $22 million.
Also within rental, ancillary revenues in the quarter were up about $65 million or 31% and rerent was up $30 million.
And we'll talk more about the increase in ancillary revenues in a moment.
Used equipment sales came in at $194 million, that's an increase of $80 million or about 10%.
Pricing at retail in the quarter increased over 7% versus last year and supported robust adjusted used margins of 47.9%, and that represents a sequential improvement of 520 basis points and is 190 basis points higher than the second quarter of 2020.
Used sales proceeds for the quarter represented a strong recovery of about 59% of the original cost of fleet that was on an average over seven years old.
Let's move to EBITDA.
Adjusted EBITDA for the quarter was $999 million, an increase of 11% year-over-year or $100 million, that included $13 million of one-time costs for acquisition activity.
The dollar change includes a $141 million increase from Rentals and in that, OER was up $125 million, ancillary contributed $10 million and rerent added $6 million.
Used sales were tailwind to adjusted EBITDA of $12 million and other non-rental lines of business provided $6 million.
The impact of SG&A and adjusted EBITDA was a headwind for the quarter of $59 million, which came mostly from the resetting of bonus expense.
We also had higher commissions on better revenue performance and higher discretionary expenses like T&E that continue to normalize.
Our adjusted EBITDA margin in the quarter was 43.7%, down 270 basis points year-over-year and flow-through as reported was about 29%.
Let's take a closer look at margin and flow-through this quarter.
Importantly, you'll recall that our COVID response last year included a swift and significant pullback in certain operating and discretionary costs that was especially pronounced in the second quarter and is impacting flow-through this year as activity continues to ramp and costs continue to normalize.
We expect this will play through the rest of the year, notably in the third quarter.
And specific to the second quarter, we've shared in previous calls that one of the costs that will reset this year is bonus expense from the low levels incurred last year.
As a result, we had an expected drag in flow-through in the second quarter as we reset and now true up this year's expense.
Flow-through and margins were also impacted as anticipated by acquisition activity, including the one-time costs I mentioned earlier.
I also mentioned higher ancillary revenue in the second quarter, which represents in part the recovery of higher delivery costs.
Delivery has been an area where we've seen the most inflation pressure, including higher costs for fuel and third-party hauling.
While recovering a portion of that increase in ancillary protected gross profit dollars, it impacted flow-through and margin this quarter as a pass-through, and we expect to see that play out over the next couple of quarters as well.
Adjusting for these few items, the implied flow-through for the second quarter was about 46% with implied margins flat versus last year.
With our expenses normalizing, that reflects the cost performance across the core that came in as expected.
I'll shift to adjusted EPS, which was $4.66 for the second quarter, including a $0.13 drag from one-time costs.
That's up $0.98 versus last year, primarily on higher net income.
Looking at capex and free cash flow.
For the quarter, gross rental capex was a robust $913 million.
Our proceeds from used equipment sales were $194 million, resulting in net capex in the second quarter of $719 million, that's up $750 million versus the second quarter last year.
Even as we've invested in significantly higher capex spending so far this year, our free cash flow remains very strong at just under $1.2 billion generated through June 30th.
Now turning to ROIC, which was a healthy 9.2% on a trailing 12-month basis.
Notably, our ROIC continues to run comfortably above our weighted average cost of capital.
Our balance sheet remains rock solid.
Year-over-year, net debt is down 4% or about $454 million.
That's after funding over $1.4 billion of acquisition activity this year with the ABL.
Leverage with 2.5 times at the end of the second quarter.
That's flat to where we were at the end of the second quarter of 2020, and an increase of 20 basis points from the end of the first quarter this year, mainly due to the acquisition of General Finance in May.
I'll look at our liquidity, which is very strong.
We finished the quarter with over $2.8 billion in total liquidity.
That's made up of ABL capacity of just under $2.4 billion and availability on our AR facility of $106 million.
We also had $336 million in cash.
Looking forward, I'll share some color on our revised 2021 guidance.
We've raised our full year guidance ranges at the midpoint by $350 million in total revenue and $100 million in adjusted EBITDA, as we now expect stronger double-digit growth for the core business in the back half of the year.
Our current guidance also includes the impact of acquisition activity since our last update, predominantly to include General Finance.
That increase for acquisitions reflects $250 million in total revenue and $60 million in adjusted EBITDA, which includes $15 million of expected full year one-time costs.
Additional capex investment will help support higher demand.
To that end, we raised our growth capex guidance by $300 million, a good portion of which reflects fleet we are purchasing from Acme Lift.
While the fleet will provide some contribution in 2021 and is assumed in our guidance, we expect to see the full benefit next year.
Finally, our update to free cash flow reflects the additional capex we'll buy as well as the puts and takes from the changes I mentioned.
It remains a robust $1.7 billion at the midpoint and we'll continue to earmark our free cash flow this year toward debt reduction to enhance the firepower we have to grow our business.
Jonathan, would you please open the line.

user
qtrly adjusted earnings per share of $4.66.

assistant