The Warhead fill valve o-ring offers a replacement o-ring for use with airsoft gas blowback (GBB) magazines. Many fill valves have a tiny o-ring around them to prevent the loss of gas when filling the magazine. If gas leaks when filling your mag, this could result in your magazine freezing-up, not to mention the loss of gas. If your magazine never had an o-ring, try one. We think you will be pleased.
To install the o-ring, slip it over the intake valve's fill tube. This can be done by gently placing the o-ring onto a round toothpick and then aligning the toothpick with the intake valve's fill tube. Slide the o-ring off the toothpick and onto the intake valve's fill tube. The o-ring can then be pushed, using a can of green gas or a propane adapter, to its final position .