The Timer-R digital timer has a large easy to read screen, a grow room-friendly green backlit screen and an easy to use the cross button for programming. This is just scratching the surface as the Time-R has many features never before seen on a timer…. until now. The Time-R operates like a normal timer but has a multitude of other options for controlled switching that go down to one-second intervals if needed. If you want to run a fan/pump with different settings at night, or you want to dispense CO2 using precise dosing at particular times throughout the day, the Time-R has you covered. 3 MODES Timed Mode:Set precise on and off times, up to 15 times a day Repeat Mode:Turn your equipment on and off, repeating at regular set intervals - from 1 second to 99 hours Combined Mode:Using this mode allows you to run your equipment on and off repeatedly at set intervals throughout a 24-hour period. Maximum 3 group settings