Backing Disc I Use for Yellow Diamond Wheel

This is for the disc I used to back the yellow diamond wheel in my YouTube video. It’s ready to use at arrival and doesn’t require any adjustment. Please refer to my video on it’s used to improve the performance of the yellow diamond wheel:
https://youtu.be/tt2RbKMjp1U

For our behind the scenes:
https://www.youtube.com/HuiyiTan