This ratchet was recommended by an air frame mechanic who was frustrated when he needed close quarter access to screw heads. The ratchet features a 1/4" drive on one end and a 5/16" drive on the other, both reversible. Also included in the kit is a 1/4" socket adapter, three (3) #1 Phillips head bits and three (3) #2 Phillips head bits. Inexpensive to purchase and indispensable when you need it. Additional, even shorter, insert bits are available as part number 56200 and 56201.