6 piece telescopic gauge set expert quality, for measuring of bore diameter & groove width. The spring-loaded plunger expands within the hole. Knurled locking screw allows plunger contacts to be held in position, removed & measured with a micrometer. Satin chrome finish. Supplied in pvc storage wallet with ranges marked. Ranges. 8-13mm (5/16
- 1/2) length: 115mm. 13-19mm (1/2
- 3/4) length: 115mm. 19-31mm (3/4
- 1.1/4) length: 115mm. 31-54mm (1.1/4
- 2.1/8) length: 145mm. 54-89mm (2.1/8
- 3.1/2) length: 145mm. 89-150mm (3.1/2
- 6) length: 145mm.