The pin chuck is a perfect accessory for holding drills too small to be held by standard a drill chuck, comes complete with three collets. Interchangeable collets of the following sizes: 0 - 0.75mm (0 - 1/32 in); 0.75 - 1.5mm (1/32 - 1/16 in); 1.5 - 2.5mm (1/16 - 3/32 in). Shank size, 6.5mm or 1/4 inch.