Its where the air pump hose hooks into the lower section of the KA-DE manifold. Its missing the whole piece, and Im going to see if they make a plug that size.
If anyone knows that would be awesome, or if anyone has one laying around.
If you have the pipe that went in there originally you can put a nickel in then screw on just the threaded part of that pipe(cut the pipe and slide it off) and it will block perfectly.
