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

Dynabrade 40752 Switch Button
Dynabrade 53074 1/4" Right Angle Drill, .4 HP, Rear Exhaust, 5,000 RPM
Dynabrade 90672 1/2" W x 30" L 80 Grit A/O DynaCut Belt, 50/pack
Dynabrade 57101 5" Dia. Low Profile Random Orbital Sander
Dynabrade 31935 1" to 1-1/4" Vacuum Whip Hose 4" Long w/Swivel Adaptor
Dynabrade 96529 Tune-Up Kit for .7 hp Motor, Front and Rear Exhaust
Dynabrade 52933 1/4" Drill, .4 HP, Rear Exhaust, 2,400 RPM
Dynabrade 93532 7" Mandrel for Sanding Stars w/ Flexible Tip, 8-32 Male Thread
Dynabrade X62H 6" (152 mm) Dia. Non-Vacuum Dynorbital Extreme Random Orbital Sander, .3 HP, 12,000 RPM, 3/32" Orbit, Hook-Face 