Kool Stop Disc pads Avid Elixir - sintered metallic- High performance disc pads from the most trusted name in aftermarket brake pads - Organic: blend of organic materials with a top quantity resin provides excellent performance throughout the life of the pad. Organic pads have steel back plates in red - Sintered: metallic compound provides performance in extreme conditions for ultimate stopping power durability and pad life. Sintered pads have copper plated back plates - Includes pad retention spring.