The snappy system starts with the quick chuck. Six flats on the shank ensure precise location in the chuck. A sprung loaded outer sleeve makes it easy to remove attachments. This chuck is suitable for use in 5/16 inch yankee ratchet screwdrivers. specification:. Diameter of 23mm. Overall length 68mm. Accepts 1/4"" direct drive tools. accessories::. Trend snappy metal rack red tr_snap/rack/1. Trend snappy tool holder 30 pc bit set tr_snap/th 1/set. Trend snappy tool holder 60 pc bit set tr_snap/th 2/set.