Developed in collaboration with Bristol Based Airsoft, the Crimson NPAS is a totally unique, market-leading upgrade designed to deliver exceptional shot-to-shot consistency across a huge range of VFC, APFG, and Maruyama GBBRs.

If you run your rifle in the 0.9–1.2 joule range, this is the upgrade you’ve been waiting for.

Our design incorporates a tighter internal bore which allows for far more consistent FPS results at the 0.9 – 1.2 joule range, making it ideal for anyone operating within those limits. A graph has been made, by the great guys at FireSupport, at the end of our product photos to demonstrate this against the stock valve (note; this will work in many more GBBRs than just the VFC AK, full list of compatibility is below). This clearly shows just how consistent then Crimson NPAS truly is. A gamechanger for such a small cost.

The NPAS (Negative Pressure Adjustment System) allows you to fine-tune your rifle’s energy output quickly and easily using a 1.5mm hex key.

Adjustment is straightforward:

Remove bolt

Insert 1.5mm hex key through nozzle

Clockwise = reduce power

Counter-clockwise = increase power

Reassemble and chrono

Perfect for staying under limits year-round, regardless of temperature, gas choice, or BB weight.

A true must-have for serious GBBR users.

Compatible with the vast majority of VFC / APFG / Maruyama GBBRs, including:

– VFC URGI GBBR (all variants)

– VFC 416 GBBR (all variants)

– VFC BCM GBBR (all variants)

– VFC SR-16 GBBR (all variants)

– VFC AK GBBR (all variants)

– VFC 727 GBBR

– VFC M933 GBBR

– VFC M733 GBBR

– VFC M16A1 / M16A2 GBBR

– VFC XM177E2 GBBR

– VFC MP7 GBBR

– VFC SR25 / M110 GBBR

– VFC SCAR-H GBBR (all variants)

– VFC 417/G28 GBBR

– VFC PSG1 GBBR

– VFC T91 GBBR (all variants)

– VFC G36 GBBR (all variants)

– VFC G3 / HK53 GBBR

– VFC FAL / OSW GBBR

– VFC FNC GBBR (all variants)

– VFC UMP45 / UMP9 GBBR

– VFC PPSH GBBR

– APFG MCX GBBR (all variants)

– APFG MPX GBBR (all variants)

– MaruyamaISO 556 GBBR

– Maruyama APC9 / SCW9 /SPC9 GBBR (all variants)

– Marksman K1A GBBR

The material used is a stronger Nylon Polymer in the iconic Crimson red, making it extremely easy to identify on your tech bench as well as when it is installed. You will no lose track of who’s VFC NPAS is who’s (not that you will need any others after this).

Crimson, it’s red

*Installing an NPAS will require some teching knowledge and a small amount of tools. A video here demonstrates the installing process. Be careful when adjusting your NPAS to ensure you don’t totally unscrew the adjustment screw, this goes for any NPAS on the market. If you have any questions please contact us*