This is a professional quick connect. Use these to easily be able to disconnect your water line, while being able to have the water flow stop on both sides. Now you have the ability to disconnect your water line, and attach it to a separate water supply line. Great for being able to connect two independent water reservoir's or to simply have the ability to stop water from exiting a system when disconnected.

This particular product is a 1/2" NPT on one side, and a 8mm adapter on the other side. Each with auto water stop when disconnected.