These kits include a new wipers, nut seal, key's, lower bumper, as well as upper and lower bushings. The kit includes the components necessary to refurbish the Air Cushion as an option. The kit also includes a small amount of Grease as required for the rebuild. Use this kit if your post is getting worn, your wipers are torn/worn out, or if you have started to leak air from the main nut.
To rebuild a Fall Line seatpost you will need a standard cassette spline tool like the Park Tool FR-5, as well as the 9Point8 Brake Release Tool, and the 9Point8 Seal Install Guide.
Looking for real-world advice? Jadyn is an expert on 9Point8 products.