The HLC-2e by Custom Automated Products protects lights from Hot Starts.
A "Hot Start" is the situation when a ballast attempts to restart a bulb without waiting for the bulb to cool off first.
A Hot Start can damage a bulb or shorten its life.
The HLC-1e constantly monitors the power going to the light. In the event of a power failure, it will not allow the light to restart until 15 minutes after the power has been restored.