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 92585 3-1/2" Dia. x Medium Hook-Face Surface Conditioning DynaBrite Disc, 10/pack
Dynabrade 78424 4-1/2" Dia. x 3/8" Medium DynaBrite Surface Conditioning Disc, 25/pack
Dynabrade 15101 Tension Arm (for Mini Dynafile II)
Dynabrade 11004 Dynafile Screw-In Housing 
