NEWHOUSE ELECTRIC 1-5/8 in. Trade Size Heavy-Duty Steel 4-Wheel Trolley Assembly with Sealed Bearings for 1-5/8 in. Strut Channel HT4W-158S - The Home Depot
UNISTR P2750-EG TROLLEY,4WHEELS,7/1 | Crawford Electric Supply
Channel Rollers and trollies | Channel Acessories | Channel Support Systems | Electrical & Mechanical Products | Fixfirm
P2750-EG Trolley Assembly 4 Wheel Light Duty for Use with All 1-5/8" P1000, P1001, P5000, P5001, P5500, P5501 or Taller Strut Channel, Unistrut, Superstrut (2Pack): Amazon.com: Industrial & Scientific