Using Simple: Wheel Trolley For use with 1-5/8" Wide and All 1-5/8" or Taller Strut Channel, Can be used for electric hoist installation,2-way moving installation. Working in different positions: the support trolley can be applied with the support channel to set 2 directions of movement, so that the crane can work in different positions; circular arc design reduces blocking Electric hoist installation: the distance between the center of the hole at the bottom of the pillar access trolley can meet the requirements of different types of electric hoist installation hole location. Operate Steadily: Wheel Trolley Standard deep groove ball bearing installation, is very smooth no noise to it when used.Bearing welding positioning, to the stability of the work.Design Load in 900 pound. Heavy Duty Manufacturing: our roller trolley assembly is made of strengthened solid Iron+S45C for impact resistance properties to prevent rust and ;It also features a solid bearing steel pin in the strut channel. . Color: As Shown Material: Iron+S45C Package Contents: 2*Load-bearing T-type pulley 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.