Break strength: 5511 lbs.Break strength: 3969 lbs. Heavy Duty Industrial Strength. The Roller trolley is suitable for: all 1-5/8" or higher pillar channels. 2Pcs 6 Wheel Trolley Assembly Rollers Six Bearing Trolley Assembly for unistrut 1-5/8" Wide and All 1-5/8" or Taller Strut Channel.
eBay