Accuracy: ?2″.
To inspect protractor, taper gage, index plate, index head and goniometer, can also be used to set angle.
Made of special alloy steel, hardness HRC64, high stability, wear resistance and easy combination.
Can be combined to any angle with interval 6 seconds after combination (6″, 12″, 18″, … , 360?).

Air Turbine Tools 2545DM - 1/4" Angle Hand Tool Series (Long Version, Front Exhaust), 30,000RPM, 35534
Dynabrade 97568 3/8" NPT Female Safety Coupler
Insize 2230-16, EXTERNAL THREAD TAPER MEASURING INSTRUMENT, 8-16"/203.2-406.4mm, 6928640383137
Dynabrade 95676 1/4" Female Coupler with 1/4" Male Plug Assembly
Dynabrade 51926 Vane Set (4pk)
3M 03140, General Purpose Sanding Sponge CP041-6P, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Medium, 7100101537, 6/pack 