1 This item can emit carbon dioxide for honey, white wine and milk wine alcohol fermentation and can also prevent oxidation 2 It is easy to operate You simply need to fill water into the exhaust valve, insert it to the cover of the brew barrel or rubber plug on the top of the fermentation container and then cover it with the lid 3 It can effectively prevent flies from flying into the wine/beer with a cover included 4 All of the fermentation process is automatic fermentation without manual control And it can be repeatedly used for a long time 5 It is suitable for pure juice fermentation such as white grapes fermentation, honey wine fermentation, red wine secondary ferment Specifications:Material: PlasticColor: transparent as shown in the pictureSub-Type: AirlocksProduct Length: Approx 17cm / 6 7inchProduct Max Width: Approx 1cm / 0 4inchProduct Weight: Approx 12g Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures Please allow slight dimension difference due to different manual measurement Package Included:1*ValveProducts from Yuwen's store