Allows drills or impact drivers to drive hanger bolts and threaded rods Internal threads and ball shaped stop at base of hanger bolt driver allow for easy thread release Alloy-Steel for extra strength and durability Built to withstand the high torque (rotational force) of impact drivers, Impact Plus (Registered Trademark) Thread Size: 3/8" - 16, Length: 1-7/8", Shank: 1/4" hex power