For quick and accurate measurements of internal and external diameters of retaining ring grooves, o-ring grooves, and undercuts.

Precision machined from steel, hard chrome plated for extra wear resistance.

Fits all 6" vernier, dial and digital calipers with a maximum jaw thickness of 0.140".

Measures internal grooves from 0.200" up to the capacity of the caliper.

Complete Set includes the following...

• Groovemaster Size 1
• Groovemaster Size 2
• Groovemaster Size 3
• Groovemaster Size 4
• Groovemaster Size 5