Check Valve 1/4", Glass

Prevents aquarium water from back-siphoning through gas or liquid dosing lines Place anywhere on the dosing line between the water and the equipment that should be protected Ideal to protect CO2  regulators from water damage, glass holds up to corrosive carbonic acid produced from carbon dioxide in water Fits standard 1/4'' tubing Dimensions: 8.38 cm x 0.76 cm (3.3" x 0.5")