For hexagonal screws and nuts width across flats 3/8-Inch- 1 1/4-Inch); self-locking in the range of (11/16-Inch- 1 1/4-Inch); no slip and less effort required on work pieces * Replaces a complete set of spanners, ideal for tightening locknuts * The plier-type gripping movement of the jaws allows threaded connections to be tightened and released quickly using the ratchet principle * Perfect fitting grip on bolt heads and nuts with metric or imperial sizes; no rounding of gripping surfaces * Secure catching of the hinge bolt: no unintentional shifting