When tightening and loosening fasteners, socket end wrenches have an enclosed head that fits around and retains the entire head of the fastener, preventing the socket from slipping off. They have a socket on each end of the wrench, with two sockets back-to-back on one end of the handle on certain wrenches. To prevent socket loss, sockets do not detach from the wrench handle. Fasteners can be accessed in confined spaces with flex-head and T-handle driver wrenches. With a mechanism that allows the wrench to rotate freely in one direction without having to remove the wrench head from the fastener and reposition the wrench, ratcheting socket end wrenches help speed up tightening and loosening of fasteners.