Features 1.Strong Load-bearing capacity:Bold copper shaft is more load-bearing 2.Ultra-quiet:Built-in smooth ball, sliding silent, smooth and powerful 3.Smooth:The upper rail is evenly stressed, stable and smoothly pushed and pulled; the lower rail slides smoothly, labor-saving and safe to use Specifications 1.Roller diameter 23mm. Suitable for arc or square old-style shower room. 2.Material :Copper+stainless steel+nylon 3.Attention: 6-8mm door thickness, installation aperture 12mm. Installation steps 1.Take the glass door out of the track 2.Unscrew the fixing screws and remove the old pulley 3.Install the pulley on the glass door, fix it with screws, and then install the screw cover Quality Guarantee: If there is any quality problem, please feel free to contact us. Refund or Replacement for any quality problem.