The most Precise Aquarium Air Control Ever. It's accurate visual controls make it easy to see how much air is flowing through your lines. The convenient Flip Cover protects against mineral build-up and helps maintain a clean appearance. It will easily fit securely on all tank frames because of it's adjustable Universal Hanger. All plastic construction makes this valve suitable for both freshwater and saltwater aquariums.
Instructions:
Hang the device over your tank frame and connect your air line hosing to the Input nozzle. Next connect up to two airstones to the nozzles, each containing their own Flow Meter Control.