Application:Pure fermentation, such as white wine fermentation, red wine secondary fermentation,preventing back- into the fermentation during temperature changes in the room.This style airlock is typically used on fermenters up to 20 Gallon.Usage: Fill water into the exhaust valve, insert to the cover of the brew barrel or rubber plug on the top of the fermentation container, cover with the lid.Function:Isolate the air from the wine/beer, discharge CO2, prevent flies into the wine/beerUsage:1.After adding water to the exhaust valve .2.After both sides of the exhaust valves water in the parallel state, gently insert the brewing bucket lid.3.When wine ferment generated , through the exhaust valve discharged to buckets outside ,4.All the fermentation process is in normal temperature, automatic fermentation , exhaust, without manual control.5.Can be used -brewed beer, wine, cider and other uses.colour:White + redMaterial:plasticsize:Length: 17cmLower mouth diameter: 10mmPackage Contents:4 x S-Shape Air Lock with snap-on capsNote: use boiled water to boil and disinfect the Air Lock you using it. And clean it with water after using.Only the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.