100% brand new and high quality. CO2 system is designed for low cost planted tank use Easily set up/low cost/excellent quality This bottle cap is very well suitable to be DIY Co2 system's accessory that the size fits common PET plastic bottle. The composition is used as special high quality plastic for issuing great resistibility of rub, so it can be used for a long time. As for the another advantage of specific, we attached the great quality plastic O ring inside of the cap to prevent missing the Co2.Material: ABS Color: (As picture shows) Size: (As picture shows) Inside diameter: Approx 27.5mm/1.08. The item "1PCS Aquarium CO2 Accessories CO2 System Kit Generator Part Bottle Cap New CA" is in sale since Friday, January 6, 2017. This item is in the category "Pet Supplies\Fish & Aquariums\CO2 Equipment". The seller is "extraps" and is located in Hong Kong. This item can be shipped worldwide.