Billet 6061 side Picatinny rails for the PS90 receiver, sold individually and intended to be installed in pairs.

The Dorin PS90 side Picatinny rails add traditional 1913 mounting surfaces to the standard PS90 receiver, opening up the option to mount lights, lasers, IR illuminators, or other accessories at standard rail offsets. Each rail is CNC-machined from 6061 billet aluminum and Type III hardcoat anodized for durability.
Sold individually at $35; most owners install both sides simultaneously for symmetric mounting options. Hardware is included. Note that the Tri-Rail PS90 variant already has integrated side rails as a factory feature, so this product does not apply to that configuration.
The Dorin rails are the obvious starting point for adding modular accessory real estate to the PS90 without modifying the receiver. They install with the factory threaded holes on the side of the receiver and require no permanent modification.
Add the Dorin PS90 Side Picatinny Rail to your build and see how it enhances your platform.