Features: *Suitable for ordinary aquarium air pumps. Not compatible with s. Ensures -way inspection for aquarium and fish tank valves. *Prevents back-siphoning of aquarium water during power outages and safeguards your air supply. *Constructed from clear plastic. In case of any blockage, just use a paper clip to clear the airway. *Air hole diameter: 0.15 in 4 mm; Overall dimensions: 2.16 in x 0.58 in 5.5 cm x 1.5 cm (length x maximum diameter). *Reliable and high-quality check valves for efficient and safe of your aquarium air pump. Specifications: *Product Name:stop valve *Material:plastic *Size:55mm*15mm *Color:red，black，white Package Content: 10x Check Valves Note: 1. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. 2. Please allow slight manual measurement deviation for the data. Suitable for ordinary aquarium air pumps. Not compatible with s. Ensures -way inspection for aquarium and fish tank valves. Prevents back-siphoning of aquarium water during power outages and safeguards your air supply. Constructed from clear plastic. In case of any blockage, just use a paper clip to clear the airway. Air hole diameter: 0.15 in 4 mm; Overall dimensions: 2.16 in x 0.58 in 5.5 cm x 1.5 cm (length x maximum diameter). Reliable and high-quality check valves for efficient and safe of your aquarium air pump.Specifications: