From the product description, check product page for current description, price and availability:

• New and improved version of this fitting is much easier to connect than previous stock. We’ve moved the locking groove closer to the ends so the poppet in your QD doesn’t have to compress as much.
• Maybe this is a strange idea but that’s how we roll. This custom made fitting allows you to connect a liquid or gas** ball lock coupler/disconnect to both sides. It’s made so that the poppet is depressed to get full flow through both lines
• If you’ve got a multiple faucet kegerator, you’re probably used to cleaning your lines one tap at a time. There are a lot of different ways to run cleaner through the lines whether it be pumping, or maybe even dispensing BLC or other cleaners through by pressurizing a spare keg.
• The BEST way to clean lines is to use a pump because cleaner in motion works better than static. Here’s how we do it. We use a chugger pump fed from a spare pot or cooler and the output of the pump goes into the first faucet (simply clamp the hose on to the nozzle).
• The serving line goes to this ball lock jumper fitting, then into the serving line of the next faucet. On the outside of this faucet you can either run it back into your cleaner reservoir or continue to daisy chain to as many faucets as you have. Please note that if you have the faucet style where the piston sticks out of the front of the faucet, you can’t do this because it will leak at that spot.