Pawfly 6 PCS Aquarium Check Valves One Way Non return Protector Air Pump Accessories for Fish Tank,Black

For Oxygen Pumps Only: Great one-way check valves for most common aquarium air pumps. DO NOT use them in CO2 or other high-pressure systems to avoid cracking or leakage. Small & Light: Size: 4.2 x 1.27 cm (L x W); Diameter of air holes: 0.3 CM; Weight: 2.1 g. Standard ID airline tubing:4-6 mm. Add little weight to your hose for smooth airflow. Ideal Pump Protectors: Effectively prevent water backflow during a power outage or pause of the pump. Ideally protect your pump and reduce your loss when you’re at work or on vacation. Sturdy Plastic: Dependable plastic which can be tightly connected to the hose without air leaks or restrictions. Always keep your fish lively and endure long-time use. Detachable Design: Easy to detach it for cleaning and maintenance without using tools. Please stick something into the hole to poke it open when it gets clogged and restricts air flow.