The Fish tank bubbler Made of Strong material, fish are happy and safe,help the virtuous cycle of water and air Automatic sinking, do not need sucker fixed, always connected to the air tube Low pressure will produce small bubbles, high pressure will produce a large number of finer bubbles, the whole surface can release bubbles, unaffected by the climate always open Material: Mineral & Plastic. The aquarium bubbler bar fits for 3/16″ inner diameter tube, Stone Length: 10″