12V DC relay remote control ON/OFF switch, with NORMALLY-CLOSED RELAY and control by water-resistant remote key fob. 

NORMALLY-CLOSED RELAY: initially relay is in "closed" position and circuit is connected. when remote button is depressed, relay will then opens up and circuit will be disconnected. this operation will cycle each time remote control button is depressed.

Best for use in situation where you want your circuit stays connected at all time but occasionally be able to turn it off, remotely. 

For remotely turn off and on 12V DC application uses in automobile, motorcycle, boat, RV, boat, home, garden, hunting tool and any 12V device

receiver comes with wires for easy installation.

Specs:
Kit included: 1 switch receiver box, 2 remote transmitter (battery included)
Remote mode: on and off, toggle mode
Remote range: ~80ft/~20m

(Remote range and signal strength depend on where device is setup, battery strength, interference, etc.)
Receiver Input: 12V DC only 
Receiver output:12V DC 
Relay standby state: normally closed
Maximum load: 15A

Operate Temp: 0F~135F

Dimension (Receiver): L 2" x W 7/8" x D 1"

How does this remote work?
When 12v is feed into the switch's red/black wire, it will passed through the closed relay and feed to the output white wire and automatically turn on your device. when the remote button is pressed once, the relay in the receiver box open up and disconnect the output power, therefore turns off your device.