This 338-piece metric kit is one of many custom kits designed by Sonic. The kit consists of 5 medium chemical resistant, CNC-machined foam inlays, covering essential 1/4", 3/8" and 1/2" ratchet and socket needs, hex and TX key sets, 16, 18 and 21mm spark plug sockets, three styles of wrenches, screwdrivers, pliers, chisels and hammers.