This is a pair of Ultra Reservoir Shock Caps for X-MAXX®. X-MAXX® fans - Are you ready to take the Performance of your X-MAXX® to the Next Level? Introducing Pro-Line's Ultra Reservoir Shock Caps that fit directly onto the stock X-MAXX® shocks and transform them into fully functional Reservoir Shocks! The additional Reservoir provides more oil volume to your X-MAXX® shocks which results in cooler shock temps and improved shock consistency.