Size:(Long tail)Length 23.5mm, Diameter 14mm. (Short tail) Length 18mm, Diameter 14mm.Accepts accessory rotary bits with 1/32 inch (0.8 mm) to 1/8 inch (3.2 mm) shanks.
Apply to:suitable for rotary tool models 275, 285, 398; Also suitable for models 750, 770 and 781
Compatible: with rotary tool models 4000, 400, 3000, 398, 300, 285, 275, 200, 100, 8220, 8200, 800, 780, 770, 7700, 750.