Manufactured from chrome vanadium steel and are fully chrome plated with a mirror finish. All have ball retaining groove on each face of the square drive. Conform to DIN standards. Overall length: 55mm. Bit length: 20mm. The benefits of having properly organised tool storage and control include: The red underlay gives instant recognition of a missing tool and the top layer of foam is durable for industrial use. Finger cut-outs make tool retrieval very easy. This is extremely efficient as it eliminates the struggle of digging out the tools multiple times. Rapid tool location for instant use. Protection of expensive kit. Prevention of tools sliding around during transit. Avoids loss or theft of tools. Easy to see if tools are not replaced. Safety and peace of mind as tools will not be left within aircraft/vehicles/machinery.