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 51204, Trizact Cloth Belt 237AA, A30 X-weight, 4 in x 90 in, Film-lok, Full-flex, 7010308049, 50 per case
Insize 4120-10N, METRIC THREAD RING GAGE, NO GO, M10x1.5, 6928640341762
3M 26054, PPS Series 2.0 Adapter, Type S18, 3/8 Female, 18 Thread NPS,
4 per case
3M 33439, Cubitron II File Belt, 33439, 60+, 10 mm x 330 mm (3/8 in x 13 in), 7100033194, 10 belts per carton, 5 cartons per case
3M 33446, Cubitron II File Belt, 80+, 1/2 in x 18 in (12.7 mm x 457.2 mm), 7100033186, 10 belts per carton, 5 cartons per case
Dynabrade 98263 3/8" NPT Male Plug
3M 65491, Pro Grade Precision Ultra Durable Universal Hole Sanding Disc, DUH5220TRI-10T, 5 IN x UH, 220, 7100202880, 10 per pack
Dynabrade 78425 4-1/2" Dia. x 3/8" Coarse DynaBrite Surface Conditioning Disc, 25/pack
Dynabrade 92116 1/2" W x 12" L 320 Grit A/O DynaCut Belt, 50/pack
3M 85492, Scotch Foil Tape 3311-10A, 2.0 in x 10 yd (50.8 mm x 9,1 m), 7010383663 