Here's a cool new valve for makers interested in pneumatic systems, hydraulics, inflatables, projects with compressed air, and the like. These air valves, also known by other names like, automatic bleeding valve or air release valve, are typically used to passively release air from a pressurized container. There are three ports on this valve, and you can sort of think of the valve as a pneumatic 'relay: The middle port with the flange is the 'common' connection. When powered, the common middle port and the plastic end port closest to it are connected and the metal end port is closed (no air flow in or out). When de-powered, the common middle port and the metal end port are connected, and the plastic end port is closed (no air flow in or out). Of course, you'll need an air pump to generate pressure either positive or negative. Comes with a cable with what looks like a JST XH compatible 2.5mm plastic connector on the end.