Specification Product Name: Two Bearing Trolley Assembly Material: Steel Finish: Zinc Plated Steel Trolleys Size： Steel plate thickness1/4" (6mm)， Steel plate hole diameter: 9/16" (14mm)， Design load: 150 lbs at 600 rpm; 220 lbs at 300 rpm; 280 lbs at 100 rpm. Break strength: 2200 lbs. Heavy Duty Industrial Strength. The Roller trolley is suitable for: all 1-5/8" or higher pillar channels. Anchor Shackle Size: 1 Pcs 1/2"(12mm) Bow Shape Screw Pin Anchor Shackle, one-way screw, bolt design, Max Open Width: 0.75" (20mm), Working Load Limit: 1400kg / 3086lbs. Trolley Wheel Weight:790g Advantage Roller Trolley Standard deep groove ball bearing installation is very smooth no noise to it when used. Bearings and pins are firmly welded, work stably, and can be used for a long time. Package included Package included: 2 pcs x 2 Wheel Trolley Assembly