COMBO trolley hangers are made to handle doors up to 600-pounds. There is no metal-to-metal contact. Tough, ball-shaped, self-lubricating, Delrin-500 trolley wheels roll easily in the round COMBO track and are virtually impervious to wear. Teflon grease is added for even smoother operation. Polished-steel roller-bearings are optional in all trolley wheels for ultimate rolling ease with heaviest doors. Long, underslung wheel bases eliminate chattering and bucking. All metal parts are zinc-plated. 

Dimensions: 9-1/2"

149550 - Heavy Duty Offset Bolt Trolley Hanger with Ball Bearing