I bought this through Amazon, and have used it extensively to produce 3/8" finger joints for cabinet drawers, and for producing other width dado grooves. It is extremely precise, you can control the width of the dado to within .004"( good enough for most joinery techniques), and it is very easy to mount and use on your table saw. I built my own zero-clearance table insert so that the blades just come up through the insert with very little space to the left or right.