The Apollo-1 is used to control short cycle equipment like, pumps, CO2 regulators, or anything that needs short cycles. The Apollo-1 has 3 seconds to 30 minutes "on-time"? and 3 minutes to 8 hours "off-time" and has a built in photocell to activate equipment during the "day" position, "night" position, or the "both" position for pumps and other equipment.