With a range from 5/32″ to 1/2″, this set covers a useful spread of common imperial sizes. 1 xset of 11 imperial 12-point sockets on a rail: 5/32″, 3/16″, 7/32″, 1/4″, 9/32″, 5/16″, 11/32″, 3/8″, 7/16″, 15/32″, 1/2″.