Drive or remove most security screws. Not a phillips, slotted, square or combo drive bit in this unique woodtek 32-piece security driver bit set: made from precision machined chrome vanadium steel, these bits are designed to drive or loosen a wide variety of security screws. 75mm long (2-3/4") power drive style bits. 1/4" hex shank fits standard bit holders. set includes 4 spanner (4-10mm), 4 tri-Wing® (4-6mm), 3 torq-Set® (6-10mm), 9 star (2-6mm) and 12 hex (six 2-6mm, six 5/32"-5/64"),drivers. bits and holder are held in a soft plastic casetaiwan.