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 Flatback Tape 2517, Medium Brown, 100 mm x 55 m, 6.5 mil, 8Rolls/Case, 7000088504
3M 85492, Scotch Foil Tape 3311-10A, 2.0 in x 10 yd (50.8 mm x 9,1 m), 7010383663 