Materials: 316L Stainless Steel Plates Copper Braze (99.9% Copper) Connections: 1" MNPT BTU rating: up to 500,000 BTU/hr Flow Rate: up to 35 GPM Applications: BT Series heat exchangers designed especially for hydronic heating and cooling applications, including radiant heating, solar hot water heating, ice and snow melt applications, domestic hot water heating (DHW), outdoor wood stove and wood boiler heating, and as a general alternative to shell & tube heat exchangers.