This is an oversized plenum for the AirVenturi Avenger in all forms.
Fitment is straight forward but the stock will have to be cut or clearanced in order for the plenum to fit into or through the stock.
My .25 Avenger with this same 10cc plenum is currently shooting 29 grain slugs at 990 fps with the hammer spring all the way in and the reg pressure set at 2,600 psi. It is capable of 75+ fpe with this plenum and some internal mods. I have detuned it for lower air consumption and for use with the 29 grain slugs.
Bleed all air pressure for your Avenger before starting this work.
Remove the stock for your Avenger
There is a small set screw at the back of the air block, trigger side that needs to be loosened to remove the stock plenum cap. Once the small set screw is loosened the cap can be unscrewed from the plenum. I used a small pair of needle nose plyers opened up with the nose of one jar in each hole in the cap to loosen the stock cap.
Once the stock cap is removed simply thread the AE Swede plenum back in by hand until the threads are not visible at all. Next tighten the small set screw on the back of the air block back down and install the stock.
Refill your Avenger with air.
Bleeding of air pressure can now be easily done by loosening one of both air pressure gauges only 1/2 to 1 full turn most with most Avengers. The gauge does not need to be removed as it uses a seating seal and just needs to be loosened.