["Features: The fermentation airlock is made of high quality BPA-free polypropylene and the stopper is made of food grade rubber, which is a good and helper for the fermentation food. Brewing airlock can be used for preserving, wine making, beer brewing, fermenting sauerkraut, kimchi that can satisfy your daily fermentation need. Simple to press the stopper onto the carboy, insert the beer airlock to the stopper, pour some water into airlock and cover the lid to complete all operations. Brewing airlock makes easier for the fermentation caused it could effectively isolate the air to prevent oxidation and allow the whole fermentation process to be automatic fermentation and exhaust at normal temperature without manual control. Specification: Material: Plastic Color: Transparent as picture Sub-Type: Airlocks Size: Length 170mm/7" Tube Diameter:10mm/0.4" Quantity: 5 Pcs. Note: 1.Transition: 1cm=10mm=0.39inch 2.Please allow 0-3cm error due to manual measurement. pls make sure you do not mind before you bid. 3.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes 5Pcs Fermenting Air Locks."]