uxcell 2 Pieces 9.5mm Diameter Screw Thread Muffler Air Bubble Stone for Fish Tank Brand new with high quality Brass quick coupler, features male thread to hose barb type, straight design Commonly used to connect various pipes, such as air pipe, fuel pipe, water pipe Applied to pneumatic piping as quick fitting joint, easy to connect in a quick and simple way. It is suitable for fresh water, salt water aquarium and hydroponic use.