Resolution .00005″/0.001mm.
IP54 dust/waterproof.
Buttons: on/off, set, inch/mm, ABS/INC.
Data output. LR44 battery, automatic power off.
Carbide measuring faces. Ratchet stop.
Supplied with extension rods.
Setting rings are included (except part no. 3128-12).

3M 28713 ROLOC DISC PAD TR, HARD 4 IN 5/8-11 INTERNAL, 7010298961
Insize 1179-300, DIGITAL RTJ RING GROOVE CALIPER, inside diameter of RTJ ring groove .4-12"/10-300mm, outside diameter of RTJ ring groove 1-12"/25-300mm, 6928640302565
3M 83980, Roloc Disc Pad TR, Extra Hard 4 in 5/8 -11 Internal, 7000119300 