Delta Model 17-924 mortising attachment. Converts drill press into mortising machine. Designed to fit Delta drill presses, but fits wide variety of drill presses. I've used it on a Porter Cable. Includes case, instruction manual and one chisel and bit set. Used once. Great condition. Note: I believe that the model 17-924 set (which costs $150-$200, depending on where you buy it) includes four sets of chisels and drill bits. This one only includes one set.