If you spend a lot of time installing and removing screws then the Ratio Driver will speed up your work by a factor of four. The geared drive mechanism ratchets the nosepiece 4 times for each turn of the handle; and the ratchet direction can be reversed with a quick flick of a switch. The Ratio Driver accepts any ¼" drive bits and includes an assortment of 8 bits in its patented handle compartment. The included bits are extra-long (3") double ended bits made of S2 hardened steel in sizes: Hex 3/32", 1/8", 5/32", 3/16"; Torx 15, 20, 25, 30; Phillips 0, 1, 2, 3; Slot 1/4", 3/16"; Roberts (square) 2, 3. 1 lbs (0.5Kg) shipping weight.