The 37 piece 3/8 in. Drive Husky mechanics tool set includes a 3/8 in. Drive Roundhead Ratchet and 3 in. and 6 in. extension bars, along with 11 SAE sockets and 12 Metric sockets, one magnetic bit driver and one ¼ in. shank bits with holder. The Surface Drive contact points virtually eliminate the rounding of fasteners. By moving the contact points away from the edge of the fastener, the area of flat contact is expanded, distributing the load over a wider surface.