Wheel Trolley For use with 1-5/8Inch Wide and All 1-5/8Inch or Taller Strut Channel, Can be used for electric hoist installation,2-way moving installation. 2 way moving installation: it can be used in conjunction with the Strut Channel to set up 2 directions of movement so that the Hoist can work in multiple positions. Applicable to all channel with 1-5/8Inch width and 1-5/8Inch thickness or thicker, compatible with for P1000, P1001, P5000, P5001, P5500, P5501. The pin shaft in the strut channel trolley bearing is made of solid alloy steel, which ensures the high strength of the Wheel trolley. Intermediate support of solid steel, high strength, impact resistance. Galvanized Zinc, rust protection Industrial doors with hanging wheels, pulleys, bearings, high-quality bearing, More wear- Colour:Silver Material:iron Package Contents: 2 * Trolley Assembly Rollers Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.