Check the listing for details. 12V-2A SOLENOID CONTROLLER- SINGLE PULSE @ DUSK AND REVERSE SINGLE PULSE @ DAWN. Color: Black, Condition: New. Listed at 15.00 USD. This unit is designed for 12vdc at a maximum of 2 amps. It contains a circuit to reverse the output depending on whether it is daylight or dark. It provides a single pulse at daylight and a single reverse pulse at dark to operate a solenoid for latching or unlatching a door with linkage and mechanisms that are not included. A LDR (light dependent resistor) is included to complete the circuit. The control box must be mounted inside a weatherproof enclosure or indoors. The LDR wires can be extended if required. The LDR wires must be installed in the screw terminals as marked. The solenoid wires must be installed in the screw terminals as marked. If you want to reverse the operation, just reverse the solenoid wires in the screw terminals. A 5.5 x 2.1 female adapter is included in the control box to receive 12vdc from a 5.5 x 2.1 male barrel connector (not included). The unit can be mounted to a wall by the attached bracket with screw holes. The unit requires complete darkness to actuate the push and a small amount of light will actuate the pull of the solenoid. One picture shows a solenoid and mechanism to rotate a latch 90 degrees with a 3/4" linear motion from the solenoid. This picture is only an example of what can be done with this controller. The solenoid actuator and latch mechanism are not included. The solenoid controller and the LDR are the only things included.