Ratchets and drive tools are used to turn sockets and socket bits that rotate fasteners for installation (tighten) or removal (loosen). Breaker bars are long nonratcheting bars used with sockets and socket bits to rotate fasteners. Ratchet accessories and repair parts are used to maintain ratchets or modify ratchets for use in a specific application. Ratchets have a mechanism that allows the tool to rotate freely in one direction without removing the wrench head from the fastener and repositioning the wrench. Socket drivers and speed handles can rotate a socket along its axis to tighten or loosen fasteners.