Single Way Valves: T-shaped structure with a straight single way for air to get through. Great to be used in fish tanks, aquariums, aquaculture, gardening or drip irrigation system. Compact Size: 3.8 x 1.5 cm. Right for standard 4 mm ID airline tubing. The layers on each joint make it connect tightly with the hose to effectively prevent slipping out. Free Adjustment: Simply twist the knob and adjust it from closed to wide open to regulate the air flow rate. Non-slip during use due to the texture on the knob surface. Reliable Plastic: Made of durable and healthy plastic for long-time use, it causes no adverse effect to your lovely fish. Extremely lightweight to be set up without effort. Easy to Install: Cut the air tube into 2 sections and insert the air control valve directly to connect them. Twist the knob counterclockwise to open and clockwise to close it. Product color: black Quantity delivered: 2 pieces
