Features:

• Protect you air pump by preventing aquarium water from back siphoning during a power outage.

• Place in your airline tubing between your air pump and aquarium water to prevent water returning down the air line.

• Total Size: 3.5 x 1.8cm/ 1.4" x 0.71"(L*D)

• Tip Outside Diameter: 4~5mm

Package Content:

• 20 x Aquarium Check Valves