Co-witness on your PPQ 4 OR 5 With this plate for the RMS, RMSc, and SMS. It sits flush with the RMSc and SMSc. This mount will also fit the standard RMS, SMS, SMS2″ Jpoint sights but with slight width overhang. The RMSw will fit but may not seal as the plate is narrower than the RMSw and its gasket.