I have added air bottles to a Benjamin Prod (see photots) and a Hatsan Jet.
You can see the Benjamin Prod in these photos.



The air gun needs to have a male Foster fitting, most USA sold air guns have that.
You will need the parts in the photos:
-90 degree Foster adapter costs less than $10 on Aliexpress
-paintball ASA adapter which again costs less than $10
-regulated air tank
-straps to keep everything together
Can use anything here.
The blue part is moldable plastic and is used to keep the air bottle more stable under the air gun.
You may find other ways to keep the entire setup stable.
You can see the Benjamin Prod in these photos.



The air gun needs to have a male Foster fitting, most USA sold air guns have that.
You will need the parts in the photos:
-90 degree Foster adapter costs less than $10 on Aliexpress
-paintball ASA adapter which again costs less than $10
-regulated air tank
-straps to keep everything together
Can use anything here.
The blue part is moldable plastic and is used to keep the air bottle more stable under the air gun.
You may find other ways to keep the entire setup stable.