The Emek Pops on/off asa allows you to easily turn the air off of your Emek marker with just a push of a button. Turn it back on by pushing the slide back towards the tank.
This also allows you to keep your air tank attached to your Emek during storage without worrying about a small leak draining your tank.
Some air tanks are difficult to unscrew from the bottom of your Emek, this upgrade makes its extremely smooth and easy.