Measure radius of external arc, arc angle of measured surface should be larger than 90?
Resolution .0005″/0.01mm
Buttons: on/off, set, inch/mm, preset (+, -)
Automatic power off, move the digital unit to turn on power
Battery CR2032, Data outputMade of stainless steel
Supplied with pin gage for zero setting

3M 26016, PPS Series 2.0 Adapter, Type S9, 16 mm Male, 1.5 mm Thread, 7100135330
3M 54763, SandBlaster Right Angle Grinder Multi-Layer Disc, 4 1/2 in 36g 9678, 7010384119
3M 26102, PPS Series 2.0 Adapter, Type S16, 3/8 Female, 19 Thread BSP, 7100135934 