By using transmitter (CB-2V), you can choose to remote control the water pump by pressing the button of the transmitter or wire a power supply to the transmitter to control the water pump when switch on the power. Receiver: 0020275(S1PU-AC220) Transmitter: 0021044(CB-2V) Online shop: http://www.carymart.com Email: katherinexjy@gmail.com Skype: gysyxjy Facebook: https://www.facebook.com/CaryMart-284396935008403/ Twitter: https://twitter.com/CaryMart305