Beam trolley is adjustable and slides along with the worker to provide maximum capacity. # 9065 - adjusts to fit beam flanges from 3-in. (76 mm) to 4-1/2-in. (114 mm) wide. # 9065-1 kit converts 8-1/2-in (216 mm) wide # 9065-2 kit converts 12-in. (305 mm) wide. 400-lbs (181,4 kg) maximum capacity.