Koolstop D640 brake pad Clarks M4 / Shimano Saint M810- M820- M640- M8020 / TRP G-Spec E-MTB- Quadiem- Quadiem G-Spec- Slate Evo- Slate T4Kool Stop disc pads are made with organic materials that are blended and bound together using a resin. The compounds do include small amounts of metal to improve the braking formula but though this is a mined material the pads are largely organic. The term semi metallic can also be used. We have found during testing that our disc pads are Rotor Friendly and provide high performance braking throughout the life of the pad. TECH SPECS Cooling Fins No Pad