This is a Whitz Racing Products Hyperglide 22 5.0 Gearbox Ceramic Bearing Kit, a pack of high performance ceramic and stainless steel bearings that are compatible with the TLR 22 5.0 Elite kits. Transmission bearings are a crucial area for reducing rotating mass, and improving efficiency within the drivetrain. Whether you're building a new kit, or rebuilding parts of the transmission, these ceramic bearings are a great upgrade for drivers looking to squeeze every gram of performance out of their vehicles. Features: Increased Drivetrain Roll Lower Friction Cooler Temps ABEC-5 Rating Si3N4 Ceramic Balls Stainless Steel Includes: (2) 10x15x4 (4) 5x10x4 Compatibility: TLR 22 5.0 Elite