... during closing.2. AC motor is more powerful and no maintenance.3. Barrier Beam/arm can be chosen from ... design for preventing plugging up in using.5. Balance spring no noise and easy adjusting design.6. Double limit methods ( ... ,,Turnstile, Tripod Turnstile,Security Tripod Turnstile,Safety Tripod Turnstile,Access Control Tripod Turnstile,Semi-automatic Tripod Turnstile,Automatic Tripod Turnstile ...