Professional quality rubber aeration hose (also used a lot in fish farms, for example) available as ring or bar. The supplied stainless steel rods are placed inside the rubber hose to weigh it down to the bottom. This has no negative effect on the air distribution! Big advantage of this system is that it can be shipped as a small parcel. If desired, the diameter/length can be shortened to adjust the size! Hose size: 18 x 28 mm, hose tail : 19mm. The air rod has a T-piece 19mm in the middle for a better air distribution compared to a connection on only one side.