3M Roloc Shank 45102, 1/4 in Shank 1/4-20 External, 5 per inner 50 per case
This shank has a 1/4 inch diameter to fit 1/4 inch collet chucks or drill chucks. It also has a 1/4-20 external thread to fit Roloc Disc Pads with 1/4-20 internal threads.