The Capri Tools Master XZN Bit Sockets are made for the most demanding professionals. Crafted from custom forged premium steel, they undergo proprietary heat treatment and are precisely machined to perform in the toughest situations. The bits are forged with premium S2 steel. These S2 steel bits are exceptionally strong and durable; they withstand high torque and do not twist, protecting both the bit and the fastener. All bits have chamfered end to ensure a smooth fit onto fasteners. The sockets are made from premium Chrome Vanadium steel, plated with our MaxChrome protective plating for enhanced durability and corrosion resistance. The set Includes regular, long, and temper-proof bits to help you work on most applications on European vehicles, and comes with our own Mechanic's Tray which fits right into any standard tool chest. Tray dimension: 15.7 in. L. x 7.5 in. W x 1.25 in. H (1.5 in. H with bit sockets stored).