Trek's exclusive ThruShaft design responds to changes in terrain faster than any other shock on the market Low Speed Compression adjustment offering three options to find your perfect match Features an oversized thermal compensator for greater temperature stability Adjust with a “fully checked” damper, your compression settings work independently, not to be bothered by each click of Rebound Shock controls optimized for frame integration and rider ergonomics MegNeg air can is not compatible with MY21 Super Deluxe Ultimate ThruShaft Only compatible with purple tokens for positive and negative air spring tuning 380lb threshold