Precision Caliper, 11 cm – 0–80 mm Scale, Locking Screw

The locking screw is what separates this from the other calipers here. Set the jaws to a measurement, tighten the screw, and the caliper holds that dimension — so it can be lifted away, carried to another site and applied there without the reading changing. Transferring a measurement rather than re-taking it is the point: re-measuring introduces a second chance to be wrong, and on paired structures the comparison is the whole purpose.

Dual graduation covers the unit problem — implant specifications and published techniques are quoted in whichever unit their source used, and converting in theatre is where errors enter. The fine angled tips let the points be placed accurately on a landmark while the scale stays readable, and the slide rule mechanism gives the smooth continuous adjustment a locking caliper needs to be set precisely before it is tightened.

Specifications