This extension for the 55 gal BoilerMaker pot increases the capacity to 100 US Gal gross capacity " perfect for a 2bbl batch size. The cylinder has an o-ring groove at the bottom that slips into the standard 55 gal pot. The extension includes a level gauge. A special tool is required for separating the cylinder from the pot after use (41089, sold separately). Since the extension is easily removed it makes cleaning easy. It also allows multiple batch sizes for extra versatility and is a very economical way to double the capacity of your 55 gal BoilerMaker pot!