This 1/2 inch multi-orifice flow control valve is designed to limit the flow of water to equipment in tankless water heater installations and also prevent inadequate heat transfer due to excessive flow. It is made of lead free alloy and has a multi-orifice cylinder design with solder connections that allows the user to select a flow adjustment of 2 1/2, 3, 3 1/2, or 4 GPM. It has solder connections. The maximum pressure rating is150 psi