The RM1600-2 is an automatic hydraulically operated main to rainwater changeover valve. It is ideal for rainwater harvesting and will switch from your tank water to your mains water supply (whenever your tank is empty, during a power outage or pump failure). This unique valve comes with 25mm (1″) inlets / 20mm (3/4″) outlet, giving the user flexibility in domestic applications up to a maximum flow rate of 50L/min. This product must be used with pumps with an auto restart pressure controller.