X-Fusion's Seal Kits have what you need to freshen up your dropper post and keep dirt out. - 25mm Kit is for posts with 25mm shafts and fits all Hilo posts with 125mm travel except for SL and Strate - 22mm Kit is for posts with 25mm shafts and fits 27.2mm models and 1st generation Hilo posts with 100mm travel in 30.9 and 31.6mm diameters - SL Kit fits SL dropper posts only - Strate Kit fits Strate dropper posts only