If you fell for a pretty face like I did, my friend @TheWestPole gave me some tips for fixing the Aleaker (<not a typo) Killer. It will make the spring loaded 510 fixed. I had tried an o-ring like someone mentioned but it didn't fix the problem. He wrote- Find a working atty with the shortest 510 pin. Screw it all the way down onto the mod 510 inserting one thickness of printer paper between the two. Clean off the area shown below with alcohol. Glue all around the joint shown below to seal the pin and fix it in place. Fully cure the glue. First thing I did was replace the super squishy bottle with one of these- $3.70 Mechanical Mod Replacement Squonk Bottle (5-Pack) 5-pack - 8ml / PE at FastTech - Worldwide Free Shipping The hole needs to be enlarged, a round needle file did the trick quickly (make sure there are no burrs left). The original bottle kind of auto-sucked at the end of the bottle, last 1/4" or so and made a big mess. Your results may vary on that. So anyway, on to the 510. There are 2 little screws on top and the thing popped out easily. Just be careful of the wires. 2 pics below show it open with an atty screwed on, and closed, no atty. The atty I used was the atty I was using. It's since been switched to an Enthion. Works the same. No gap, nice connection. Tim recommended Loctite Liquid Professional Super Glue. The local Home Depot didn't have it so I got Loctite GO2 Gel. Just fill that gap that the question mark is pointing to and let it set at least 24 hours. It's been working fine since. @b.m., this might interest you.