4R: inch in 8ths, 16ths, 32nds, & 64ths

-Reading: 360° (direct / reverse direction) / 0.05° - Accuracy: 0.2° per 180°
- Power: Press the button to power on or off. Auto shut-off in 5 minutes when not working.
- Zero: Press the button to zero.

- Blade Lock Knob: Lock the blade into position.
- Protractor Lock Knob: Lock and hold the protractor at the desired angle.
- Blade Assembly Cap: Press the Cap down to align the bolt to the Blade groove; then insert the blade. Do Not Force.
- Spirit Level at the reverse side for quick visual reference.
- Battery: 3V CR 2032, 1 piece