Amazon.com: UNISTRUT Genuine P2950-EG 4 Wheel Trolley Assembly for use with P1000, P1001, P5000, P5001, P5500, P5501 and All 1-5/8" or Taller Strut Channel : Industrial & Scientific
Amazon.com: Newhouse Electric Wheel Light Duty Trolley Assembly for use with All 1-5/8" or Taller Strut Channel, Unistrut, Superstrut : Industrial & Scientific