Precise flow control and fit Choose the size that matches your hose: 12mm (fits 0.5 inch inner diameter) or 16mm (fits 16mm inner diameter). Adjust water flow smoothly to create the ideal current for plants, fish, or coral. Durable, corrosion-resistant construction Made from PP (polypropylene) for long-lasting use. Resists rust and erosion; polished surfaces make the valve comfortable to hold and handle. Simple, low-effort maintenance To clean the filter, close both valves and set the connector to the open position. This isolates the filter and makes it easy to separate the tank from the filter for cleaning. Design saves time and reduces the hassle of routine maintenance. Versatile applications Use as a water flow control valve for aquariums or as a quick-release valve for filters, pump return lines, separators, and similar equipment. Suitable for a wide range of aquarium environments and setups. Practical use scenarios Reduce return flow for a fry or planted tank to protect delicate livestock and plants. Isolate and clean a canister filter without shutting down or draining the aquarium. Quickly disconnect a pump return line when replacing or servicing equipment. What you get Reliable flow control in two common sizes (12mm for 0.5 inch inner diameters; 16mm for 16mm inner diameters). A durable, easy-to-handle valve that simplifies maintenance and improves system control.