Hot Racing YEX156R01 Aluminum Adjustable Piggyback Reservoir Shock Upgrade for Axial Yeti XL Pair of Hot Racing adjustable piggyback (aka piggy-back, reservoir) shock upgrades Adjustable shock reservoir Double-sealed reservoir piston to eliminate piston blow-by Built in bleeder allows for the reduction of entrapped air to provide additional shock oil volume Anodized black and red for durability, corrosion resistance, and aesthetics