C.A.P. PTC-1 and PTC-2 Photocontrollers 

C.A.P. PTC-1 and PTC-2 Photocontrollers are perfect when you need to turn something ON only during daylight hours or only at night. A photocell senses whether it is day or night, and turns the device plugged into it On or OFF depending on which model you are using. 

These photocontrollers simply plug into standard electrical outlets - no hardwiring needed. Plug your equipment into the front outlet on the PTC and it's set to go. The PTCs are compact in size and weigh less than 1 lb.

The PTC’s photocell will react differently to various levels of light. The more intense and direct the lighting is, the faster the photocell will react to turn ON or OFF. An extended time-delay may be present if low light levels are present.

The PTC-1 Photocontroller turns ON whatever is plugged into it during the "day" when the lights are on.

The PTC-2 Photocontroller turns ON the device during the "night", when the lights are off.

Dimensions: 4” High X 2.1” Wide X 2.5” Deep

Specifications:

Main Power Voltage: 120 volts
Maximum Relay Amperage: 15 amps
Maximum motor size: 1/2 HP
Operating Temperature Range: 30-120° F
Operating Humidity Range: 0-99% RH
Relay Operations (minimum): 100,000 electrical / 1,000,000 mechanical

More info from the Manufacturer (PDF format - Lots of detail.)