The 30-liter plastic fermenter has both liter and gallon markings on the side for easy measuring. A pre-threaded hole is ready to be drilled out so you can attach the included tap for siphon-free bottling and racking. The durable airlock screws directly into the fermenter’s lid and when properly filled with water it lets carbon dioxide escape without letting any oxygen get in. Finally, the included Fermometer-brand thermometer sticks to the side of your fermenter so you can accurately gauge the temperature of your brew and keep it in the desired range.