O2 kategooria haagisel peavad olema pideva toimega (ühest energiasalvestist toidetav) pidurid, poolpideva toimega (kahest erinevast energiasalvestist toidetav) pidurid või inertspidurid (pealejooksupidurid). Poolhaagisel on inertspidurid keelatud.
The service brake shall be capable of being brought into action by the service brake control of the drawing vehicle; if, however, the permissible maximum mass of the trailer does not exceed 3,500 kg, the brakes may be such as to be brought into action, while the trailer is in motion, only by the trailer moving up on the drawing vehicle (overrun braking).