It is the 12 V one channel latched mode remote control (S1SL-DC12). It is also activated by 12V power supply. Paired with long distance transmitter CB-2, its working distance can be 1000m (3000ft). There is no need to go up and down the mast to turn device on and off. Using a remote controller to control device, it is very convenient to you. As regards the latched mode, it is motivated by relay group. For relay group, only one relay will be on at a time. So the big button of this transmitter only turns on the device when you press. And the small button only turns off the device.
We made a demonstration to show how to use this remote controller.