C.A.P. NFT-1 and NFT-2 preset recycling timers 

The C.A.P. NFT preset recycling timers are the simplest devices available for turning a device ON and OFF at precise intervals. No hardwiring needed - both the NFT-1 and NFT-2 are plug-n-play to use any standard electrical outlet . The equipment being controlled plugs into the front of the NFT timer. 

The NFT recycling timers can control almost any application but are ideal for NFT and Aeroponic systems. The “Plug-box” design is compact so it doesn't take up much room and weighs less than 1 lb.

The NFT-1 timer has a pre-set repeating cycle of 1 minute ON, 4 minutes OFF.

The NFT-2 timer has a pre-set repeating cycle of 3 minute ON, 5 minutes 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.)