When using artificial light, a regular schedule is important to ensure healthy plant growth.
This 1725-watt, 115-volt, 15-amp indoor mechanical timer automatically turns lights (or pumps, greenhouse heaters, etc.) on and off. Settings are programmed in 15-minute intervals allowing up to 96 settings that repeat every 24 hours (good for hydroponic flood-and-drain pumps).
While most timers have only a single outlet, this one has a pair of three-prong, grounded outlets that are both activated by the timer. A manual switch can override the preset timing, to turn your system on without losing your settings. Also a great household timer for lights and small appliances. UL and CUL certified.