Race Tech Shock Rebound Seperator Valve - 1.5mm Bleed SMRS 16125 Replace the stock shaft nut with an asymmetric valve to offer different flow rates for compression and rebound The stock low speed rebound adjuster flows at the same rate during compression and rebound which makes the lowest speed damping too mushy, causing bottoming and an unresponsive feeling during long duration hits; shock rebound separator valves correct this issue