The Tokyo Marui FNX-45 gas charger has an extremely deep filling valve and the diameter of the access pipe to it is very narrow. The combination of both features precludes the use of Abbey's standard mouthpiece extender. We present an extender specifically modified to be compatible with the Tokyo Marui FNX-45 gas charger. Simply install the modified extender on the Abbey gas canister and refilling is easy. This modified extender is compatible with all Abbey gas canisters.