These are discs produced by the OE manufacturer Borg Warner. We had issues from customers claiming that the friction material seems to pill/come loose. After we claimed that at the manufacturer, we received the following answer:
“It is allowable to have missing friction material on Inner and Outer diameter less 10% of the total friction material facing area.”
The complete reply can be found on our webpage after searching for this item.
After that we have decided to offer an alternative aftermarket friction disc kit additionally. Our ref. is B-FRD-0B5-K1 made by Dynax/Exedy