C.A.P. HLC-2e 15-Minute-On-Delay Timer 

The HLC-2e HID Lighting Controller will prevent your HID light from Hot starts. A Hot start occurs whenever your lights are turned off and then back on before the lamps are allowed to cool off. Hot starts are usually caused by power outages and they reduce your lamp’s life and intensity. 

When the HLC-2e is powered up, it constantly monitors the incoming power to your equipment. When you connect the HLC-2e to your grow lights, it will sense a power interruption, and start a 15 minute time-delay to keep the lights from trying to re-start while the bulbs cool down.

Specifications:

Main power voltage: 120 volts
Maximum amperage: 15 amps
Time Delay: 15 Minutes
Operating temperature range 30-120º F
Operating humidity range: 0-99% RH (non-condensing)

Simply plug the C.A.P. HLC-2e into your lighting timer, then plug your ballast or MLC into the outlet on the front face. Set the maximum temperature that your garden can sustain using the knob on the front. The HLC-2e power light (green) should be on at all times while it is receiving power. The red “Delay On” light will be solid for 15 minutes after powering on your light timer.

The HLC-2e 15-Minute-On-Delay Timer is warranted against defects in workmanship and parts for Three Years.

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