The Blue Spot Tools 4 PCE nut splitter is manufactured from heat treated carbon steel for increased durability and features a heavy duty 50-55 HRC chrome molybdenum nut splitting head, capable of splitting up to 27mm (1 1/16"""") nuts. Outer casing manufactured from heat treated carbon steel Nut splitting head manufactured from chrome molybdemun for increased durability Capable of splitting nuts up to 27MM (1 1/16"") 9-12mm nut splitter fits 12mm hex sockets and spanners 12-16mm nut splitter fits 14mm hex sockets and spanners 16-22mm nut splitter fits 19mm hex sockets and spanners 22-27mm nut splitter fits 21mm hex sockets and spanners Package Contents Contains 1 x 9-12mm (3/8""-15/32""), 1 x 12-16mm (15/32""-5/8""), 1 x 16-22mm (5/8""-7/8""), 1 x 22-27mm (7/8""-1 1/16"") nut splitters