6 Trolley Assembly Made with Hot-Rolled Carbon Steel of solid steel for impact resistance. and noise-free during use, bearings and pins welded firmly, stable work.Steel plate hole diameter-9/16 inch(14mm); thickness-2/5 inch (10mm). For use with 1-5/8 inch Wide and All 1-5/8 inch or Strut Channel.Design loads: 380 at 600 rpm; 540 at 300 rpm; 750 at 100 rpm. Breaking Strength: 6613 .The distance between the of the hole at the bottom of the support groove trolley can the location requirements of the installation holes of different types of electric hoists. If the fixing screws are installed in the support channel, the tram will not be to pass through the track, so the bolts that fix the support channel need to be installed outside the track.Color: silverMaterial: metalPackage Contents:2pcs 6 Wheel T Type Trolley AssemblyOnly the above package content, other are not included.Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.