The Evolution Powersports Polaris RZR XP Turbo diverter 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 to back into the intake and will cause a loss in power. The EVO BRV is a precision part that is designed for high performance vehicles (it has been tested to over 500 hp!) and is a direct replacement for the 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.