SKTREX Cable Trolley for Electric Hoist Cable,C Track Rail Festoon Cable Trolley System for Electric Crane and Electric Hoist for Unistrut 1-5/8" Wide and All 1-5/8" or Taller Strut Channel 2 PCS:
Why do trolley buses require two wires? | Viewpoint Vancouver
SKTREX Cable Trolley for Electric Hoist Cable,C Track Rail Festoon Cable Trolley System for Electric Crane and Electric Hoist for Unistrut 1-5/8" Wide and All 1-5/8" or Taller Strut Channel 2 PCS:
Wire Rope Cable Trolleys | United States of America