20 PCS Fish Tank Oxygen Pump Trachea Check Valve, 4mm (Red), 4mm (Black), 4mm (White), 4mm (Blue), 8mm (Red), 10mm (White), 12mm (White), 4mm (White Red), 4mm (White Black)

1. Material: ABS
2. Safety lock to prevent backflow
3. The aerator pump can be placed in any position, pay attention to the direction of the air outlet when installing
4. Air out directly from one end, if it can be blown through, that is, this end is the air inlet and the other end is the air outlet
5. Safe and durable, safe to use
6. Dimensions: 4mm total length 5.5 cm, 4mm blue total length 4.3 cm, 8mm total length 5.5 cm, 10mm total length 4.5 cm, 12mm total length 3.8 cm, 4mm white red/white black total length 4.2 cm
7. Weight: about 8 grams