3-Piece Airlock

3-Piece airlock. Simply remove the cap, fill the cylinder about halfway (to the imprinted line) with water or sanitizer, and replace the cap. 3-piece airlocks are easy to clean with an airlock brush should fermentation (krausen) back up into the airlock.

A 3-piece airlock is a simple plastic device used in homebrewing and winemaking to vent carbon dioxide (CO₂) while blocking oxygen and outside contamination.