This kit contains all the parts needed for scheduled maintenance and/or rebuild of B1 non-Stealth Reverb Seatposts. Includes Blue 1-Piece U-Cup Seal Internal Floating Piston (IFP) Rebuilds IFP, Poppet, Seal Head, Dust Seal, Piston, Brass Keys, and Bushing Requires RockShox Specialty Tools to perform Service: Post Bleed Tool, Oil Height Tool, IFP Height Tool B1 posts have a black return speed adjuster on the remote and "ROCKSHOX" laser-etched logos on stanchion by the saddle cradle