We make the best accessories for airguns at Air Marksman. One of those is the LOKI rail that adds ARCA and MLOK to the FX Impact line of rifles. This greatly increases the versatility of an already excellent rifle by bringing it into the modern age of shooter accessories. Until now, this had the inconvenience of not being able to access the foster fill port as easily as we’d like. Enter, the Foster Extender. While it might seem simple, this is a challenging piece of hardware. It needs to be pressure-safe, easily changed by the user, and retain the function of the original. We achieved this by reusing the original foster connection the rifle ships with. The plunger gets moved onto the extension rather than closing off the foster port directly. A cupped lip at the interior end of the extensions ensures your o-ring doesn’t blow out. Wrench flats allow for easy installation and a carefully integrate G1/8 BSPP fitting ensures safe and reliably sealing.