Feature: Twist Socket are made of top quality CrMO Steel proviede good wear resistance and durability. Twist socket sets are ideal for the removal of rounded, damaged or corroded nuts, bolts, oil drain plugs, marine nuts and bolts, exhaust manifold nuts, pipe nipples, and studs. Kit includes 9PC twist socket: 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 19mm; & 1PC. Knock-up Bar;