The Evolution Powersports Polaris RZR XP 1000 Turbo diverter valve (Blow Off Valve)is constructed of anodized billet aluminum and features very high temperature sealing o-rings.The OEM Polaris part is constructed of plastic and is a very low quality part which is prone to sticking open which will dump boost pressure back into the intake and will cause loss of power. The EVOPS BOV is a precision part that is designed for high performance vehicles and is a direct replace for OEM valve. Many different spring rates have been tried to maximize the performance and fine tune the transition from where the valve is open/closed for smaller displacement turbo supercharged vehicles Tested to 500+ horsepowerDirect replacement for OEM plastic valveBillet anodized aluminum construction with high temperature sealing ringsDoes not stick like the OEM valve is prone to.Includes pre filter