The counterweight frame is the steel structure that holds the counterweight filler blocks and connects them to the suspension ropes and guide shoes. Its total mass is normally the empty car weight plus 40 to 50 percent of the rated load, which balances the system and minimises the motor power required. The frame carries the rope hitch, guide shoes and, on some designs, a safety gear. Filler blocks are added or removed during commissioning to reach the calculated balance.