The most common type of socket wrench. The ratcheting mechanism allows the nut to be tightened or loosened with a reciprocating motion, without requiring that the wrench be removed and refitted after each turn. Typically, a small lever on the ratchet head switches the wrench between tightening and loosening mode. The advantages of the system of a ratchet wrench with indexable sockets are speed of wrenching it is much faster than a conventional wrench, especially in repetitive bolt-on or bolt-off usage and efficiency of tooling cost and portability it is much more efficient than a set of non-ratcheting wrenches, with every size head having its own handle. Fine-tooth ratchets have finer teeth on the ratcheting components - these can be useful for tighter locations. Dual-pawl ratchets click twice for each tooth on the gear, effectively doubling the granularity of the mechanism.