Replace the existing "GXP" bearings on your Trek (Madone, Top Fuel Carbon, Fuel EX Carbon, Remedy Carbon, Carbon Hardtail) or Gary Fisher (Superfly 100, Carbon Road) bottom bracket. For replacing your existing bearings when running SRAM, Bontrager, and TruVativ GXP cranksets. Includes two (2) replacement CHROMIUM STEEL cartridge bearings and one (1) BB90/95® SPECIFIC drive side silicone seal (Re-use your existing stainless steel end cap on the non-drive side). Grade 10 steel ball bearings are matched with hardened chromium steel races. Packed with marine grade grease. Please note that this kit is specific to "GXP" cranksets and therefore includes the special non-drive side bearing with an extended inner race.