This CO2 Adapter has the same size and thread as an 88-gram CO2 cartridge. The adapter can be used to shoot 2×12 gram CO2 cartridges in your airgun. Replace your 88 gram CO2 with this adapter in your Umarex Javelin.

Used to convert 1-88g capsule to 2-12g capsules
The adapter can be removed without allowing CO2 to escape
Can be used in any rifle that operates using an 88-gram CO2 cartridge