One counter reads in the plus direction and another in the minus directiion, so incremental measurement can be made in either direction
Carbide tipped scriber
Made of stainless steel (except the base).
With driving wheel. With dial test indicator holder.
Supplied with dust cover
Optional accessory: clamp for protracotors (code 2372-CLAMP)

3M 26120, PPS Series 2.0 Adapter, Type S28, 17.5 mm Female, 19 TPI
Thread, 7100135956
3M 26022, PPS Series 2.0 Adapter, Type S12, 10 mm Male, 1.0 mm Thread, 7100135943 
