HFS Plate chillers are made of high-grade 304 stainless steel and brazed with 99.9% copper. Offering superior heat exchange performance in a simple effective design. Plate chillers work by running cold water through every-other plate, and running wort through the plates in between. This maximizes the surface area for the fastest cooling possible, getting your wort to a safe fermenting temperature much faster than immersion chillers ever could. Plate chillers can be operated with a gravity system or with a pump. You can also save on water by utilizing a closed-loop cold water pump system. The A series of plate chillers measures 2.9" x 7.5" in surface area and is available in various plate amounts. Wort-in and wort-out connections are 1/2" NPT fittings while the water-in and water-out fittings are 3/4" (standard garden hose). These limitations are far beyond any brewing needs, based on our belief that over-engineered is better than just meeting the standards. HFS Plate chillers come standard with a 1-year manufacturer warranty and a 30-day money back guarantee. They are also UL listed and CE certified for standards in manufacturing. NOTICE - COPPER SAFETY - NOTICE This item uses copper brazing, which according to the FDA section 4-101.14 is completely safe to use with brewing equipment. Many brewing kettles, pots, and other hardware are made completely from copper. Wort will come into contact with a very small amount of the copper brazing inside this chiller which is completely safe and food grade per FDA regulations. 4-101.14 Copper, Use Limitation. (B) Copper and copper alloys may be used in contact with beer brewing ingredients that have a pH below 6 in the prefermentation and ferment fermentation steps of a beer brewing operation.