Features: Ensuring safety of your aquatic life with reliability aquarium check valves, aim to prevent water backflow. These check valves feature a compacted size, and are crafted from durably plastic for long terms use. Great for both novice and experienced aquarists, these valves are a must own accessory for anyone seek to maintain a healthy underwater environment. Practical and easy to install, check valves are perfect for home aquariums, pet store displays ensuring a clean and safe habitat. Enhances your aquarium maintenance with engineered check valves, making them essential component of your aquarium supplies. Specifications: Texture: ABS Size: 4.3cm/ 1.69in Type: Blue, Black Small, Black Large, Clear, 1 Package Includes: 30pcs Aquarium Check Valves note: 1: Please allow 1-2cm errors due to manual measurement, ensures that you not mind before your order. 2: Due to the differences between different monitors, the picture may not reflect the item actual color.