Blichmann Small Herms Coil allows your kettle to be a cooling system. Constructed with 304 Stainless Steel, this 25 Ft. long tube coil can withstand up to 50 psi. It is designed to fit Blichmann 7.5 to 10 Gallon Brew Pots. The Herms coil is made to recirculate wort through the coil allowing you to maintain a constant temperature. It is recommended to use a whirlpool to improve heat transfer, which will increase efficiency of your strike temperature and reduce time by 30%.