Refill adaptor needed to refill the Gunpower stealth rifles. This adaptor has a 1/4 BSP thread to the Gunpower bottle thread. If you have a dive bottle and hose, then this will screw on in place of the hose, onto the large metal DIN Adaptor. If you are fitting to a pump and hose, then you will also need the 1/8 - 1/4 BSP adaptor. ..