Forged from high quality Chrome-Molybdenum alloy steel for long life. Each impact socket features a radius corner design, causing the socket to grab the sturdy wall of the fastener instead of grabbing the corners. Packaged in a durable heavy duty blow mold case for convenient storage and transport. Fully Guaranteed This 13 piece 1/2" drive metric universal impact socket set is designed to extend the life of fasteners! Sunex Impact Sockets tackle the toughest jobs with solid durability that keeps them pounding job after job. This set includes the following: 12-24mm.