RockShox Vivid Coil Ultimate D1 Rear shock 185x55 Shaft Eyelet: Standard Body Eyelet: Trunnion Reb55/Comp37 Lockout 45 Trek Fuel EX Gen6 2023-2025Theres a reason everyone loves coilthe feel is unmistakablesupple off the top, supportive through the mid stroke, and backed by Adjustable Bottom Out for confident end stroke controlgiving you unwavering consistency and predictability. RCT2 damper providing a wide, usable range of Low Speed and High Speed Compression (HSC) adjustments without any cross talk Base valve with 40% reduction in IFP forces, making it the most supple shock on the market