For sale is a Big Drilling and tapping quick-change attachment Stock No 520-102 Set incl: Drilling, tapping quick-change attachment DT24 Horiuchi drill chuck 13 m/m MG (10) Holders: 5/16, 3/8, 3/4, 1/2, 5/8, 1/4 (x2), 7/8 (x2)