The Apollo? 17 is a versatile digital timer that?s simple to operate. It only takes four buttons to control the functions of the timer and features an extra-large easy to read LCD display. A variety of schedules can be programmed in minutes and hours using 16 different ON and OFF schedules. Internal battery backup feature saves settings in case of a power failure. The Apollo? 17 may be used to control CO2, fan, pump, light mover, etc. Enclosure resists dust, rust and moisture. 15 Amps maximum/120 Volts/60 Hz.