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