P90TR

The P90TR (Triple Rail) variant, also known as the "flat-top," was introduced in late 1999. It features a receiver-mounted triple MIL-STD-1913 (Picatinny) rail interface system, or "Triple Rail," for mounting accessories. There is one full-length rail on the top of the base and two rail stumps on the sides of the receiver. The side rails serve to mount accessories such as tactical lights or laser aiming devices, while the integrated top rail will accept various optics with no tools or additional mounting hardware required.