Swing lock design allows access while maintaining the swing angle.
Swing angle is 180°,  locked 8 steps (Able to lock each 22.5°)
Move the ratchet 5° by fne gear 72°. The ratchet is driven by a fine angle of 5° with 72 gears.
Ratchet part has the intensity for a final tighten.
Able to discriminate the tightening and loosening rotation direction.