This is the adaptor for the new HPA capsules Ref. 17947 and is required to refill the capsules.
The HPA capsules are similar in size and shape to a CO2 capsule, but with a refillable valve are the latest innovation in the Airgun industry. Using a container similar in size and shape to a CO2 capsule, the HPA capsule is a cost efficient tool in your Airgun and Airsoft arsenal. The refillable valve featured on the capsule allows for easy refilling. An air pump conveniently stored at home can for example be used to refill the capsule.
Using this system also means the capsule pressure can be adjusted making the muzzle velocity in the Airgun adjustable.
Note that results may vary depending on the internal CO2 system and build quality.