Overview
Improve optic alignment and consistency on your FN PS90/P90 with the Haga Defense Gen 4 Cheek Riser. The PS90’s high height-over-bore (HOB) can pull your eye off the optic when you maintain a proper cheek weld. This riser elevates the cheek weld by approximately 1", helping align your eye to the sight line for faster pickup and repeatable shots.
Key Features
- ~1" cheek weld increase for more natural optic alignment.
- Lightweight, durable nylon construction (approx. 4.3 oz).
- Built-in steel QD sling mount for secure single-point or two-point setups.
- M-LOK slot on each side for additional sling or accessory mounting.
- Easy installation using included hardware.
- Made in the USA
Compatibility & Fit
- Fits FN PS90 and P90 stocks.
- Works with both newer, wider stocks and older, narrower stocks (see install notes below).
What’s Included
- Cheek Riser
- Mounting screws & nuts
- Spacer washers (for older stocks if needed)
Installation Instructions
- Set the fire selector to “S” (safe).
- Remove the magazine by pulling the catch rearward and lifting the magazine free.
- Pull the cocking handle fully rearward and, through the magazine well, visually confirm the chamber is empty. Release the handle if clear.
- Using a 3 mm hex tool, remove the two top screws and nuts at the back of the factory stock.
- Slide the cheek riser onto the stock until its holes align with the factory holes.
- If the fit is snug: install the included screws and nuts and tighten.
- If the fit is loose (older, narrower stocks): insert the included washers between the riser and stock on each side, then install and tighten the screws and nuts.
Notes
- M-LOK accessories are sold separately.
- Built-in QD cup is steel for durability.
Why It Helps
By raising the cheek weld about an inch, this riser compensates for the PS90/P90’s higher HOB, bringing your eye into alignment with red dots or low-power optics. The result is a more consistent head position, quicker sight acquisition, and improved comfort—on the range or in defensive configurations.
