Mains Switch Over Devices are used when you may run out of water in your rain water tank and need to switch back to mains water. There are a number of options available.
Bianco Rainsaver MK4e - $528.00
Davey Rainbank KRB1 - P.O.A
Davey Rainbank KRB2 - P.O.A
Davey Rainbank KRB3 - P.O.A
Davey Rainbank KRBS1 - P.O.A
Davey Rainbank KRBS2 - P.O.A