- Measurement range of 4.0 to 8.0 and precise to 0.0002, with or 0.00025 of accuracy
- Three alloyed-steel contact points for durability
- Three-point measurement method for direct measurement of holes and bores
- Contact point geometry allows the instrument to measure to the bottom of blind holes
- Set includes four complete display units, two setting rings, extension rod, and fitted wooden case