Mechanical timers are a popular and reliable option that don't require backup batteries nor do they need to be reset in the event of a power outage. Our indoor 24 hour timer is perfect to turn lights on and off in your home as a security feature when you're not home, or it can activate other electrical items when needed. Mechanical timers are incredibly easy to set up and operate using a 24-hour dial and require you to set them manually via segments, pins or trippers.