After spending too much money on impact sprinklers at the big box stores, I ordered two of these from Amazon.  In my opinion, nothing I've tried before comes close to this quality!  These sprinklers rotate smoothly, are easy to adjust, and they have a very well-built feel to them.  I paired mine with the Orbit 1/2 inch curved tube sprinkler base, model 58030, and the results are great.  No more driving spikes into the ground!  I added a five inch nipple and coupling between the Orbit base and sprinkler head, along with a liberal amount of teflon tape.  It keeps me from having to bend over so far to fine tune the adjustments on the sprinkler.  This is a quality product!