Wera Zyklop extension with flexible-lock system. When activated, sockets are secured and permanently fixed, avoiding unintentional loss. This 1/2" Zyklop "flexible-lock" extension features a free-turning sleeve for rapid tightening and loosening of screws and nuts. It is designed for 1/2" square sockets with ball lock. The flexible lock system allows for either locking or rapid exchange of the attached tool. Made from chrome vanadium steel and matt chrome-plated.