This Mil-Spec Picatinny rail replaces the non-spec side rail found on the PS90 and P90 TR. It has 5 slots to the original 1 and allows you to mount a larger array of accessories. Operators using wide-based optics such as the Eotech have found that accessories won't fit on the factory side rails for lack of clearance. Our rails extend further than the original to overcome this problem. They also feature an offset mount to allow for additional clearance, up or down, as needed. Rails are totally ambidextrous and attach to either side of the receiver using existing threaded holes. $25 per rail.