Brake pad compound is important when it comes to the performance of brakes. The two most common brake pad types are resin and metal. Resin pads add more modulation and noise control over metal brake pads and metal pads offer more power and fade resistance. The Shimano N04C Disc Brake Pads are the metal brake pads designed for the new XTR M9120 hydraulic disc brakes with 4 pistons. If you want more raw power out of your pads then you'll love the Shimano N04C Disc Brake Pads.