Shown in photo is the automatic flusher valve-the spiralfast connector and 3 trellis clips.
The flusher valve allows faster more even filling of your lines as it allows the air pressure to escape. Once the water has reached the valve it shuts off.A wedge supplied with the valve hold the flusher open for sytem cleaning.
They can be supplied in 2 common sizes. The spiral fast tensioner is a qwik fit system requiring no tools.