DescriptionAquarium CO2 bubble counter, when the regulator is open, you will be able to calculate your CO2 injection rate by counting how many bubbles pass through the counter perminute, with the piece of mind that your equipment is protected in theevent of water siphoning back towards your equipment.Features- Color: As shown. - Material: Metal. - Size: 10.5x4x3cm - Essential CO2 tracking tool of aquarium plant tank. - Effectively count the CO2 quantity being released into the aquatic plant tank while attached to a CO2 regulator. - A must have forany tank with CO2 injection, a bubble counter allows the user toestimate the CO2 injection rate by counting how many bubbles passthrough the counter per minute. - A check prevents water from your aquarium from siphoning back into fragile and expensive CO2 equipment such as regulators and solenoids. - Perfect to get an accurate bubble count without the need of bulky and expensive equipment. - Warm Tip: Dear buyer, Due to lighting effect, monitor's brightness, manual measurement and etc, there could be some slight differences in the color and size between the photo and the actual item. Sincerely hope that you can understand! Thank you!