I'm so happy with this switch. Great purchase and at $21 US it was a great value. 5-stars! Here's the journey I went thru installing it... I'm not an electrician by any stretch, although I am smart enough to turn off the main breaker to avoid electrocuting myself. When I removed my old dumb switch, I noticed it just had 2 black wires attached to it. The dumb switch breaks the circuit, and the lights go out. Simple. How hard could this new smart switch be, right? Turns out the smart switch is more complicated and requires a "neutral wire". Huh?? What's that??? My house was built in 1961, 2 decades before the "neutral wire" was standard (I googled). I never even noticed the "neutral wire required" on this product's listing, and frankly I had no idea what a neutral wire even was. I hooked up the smart switch as best I could and it didn't work. At that point I resigned myself to the fact that this switch wasn't compatible with my old 60s wiring. I almost gave up. The next day, I did more googling and looked deeper in my old wiring and noticed a cluster of unused white wires hidden in the back. I thought MAYBE these were neutral wires. It was worth a shot! I attached one of these mystery white wires to the white neutral wire hookup on the switch, and to my dismay, it STILL didn't work! For the second time, almost gave up. Then I decided to try one last experiment. In my wall, there are TWO black wires. In my total lack of electrical knowledge, I assumed they were interchangeable...I mean, they are both the same color, so logically that would mean they are the same, right? With the old dumb switch these 2 black wires are interchangeable, so why would a smart switch be any different, right? Turns out one of these black wires is the "hot" wire, and the other one is the "load" wire...but since they are both black, I had no way of knowing which was which...and since they were both colored black I made the assumption that they were interchangeable. NEVER assume anything! With literally zero confidence that it would work, I tried reversing the black wires, and voila!!! It worked! All my hard work and perseverance paid off. The moral of the story is DON'T GIVE UP! Programming it was fairly easy. Just make sure your program uses "MO TU WE TH FR SA SU" day setting (every day of the week displayed at the same time). I skimmed the manual and ignored that part at first, and just made a program for one day. You can also store up to 18 different programs. I only needed 1. The "Random" feature is really useful too. It just randomizes the on and off times by a 30-minute random window. So, if you program the lights to turn on at 8 PM, it will pick a random time within a 30 minute window of 8 PM (up to 15 minutes before, and/or 15 minutes after). This just makes the lights appear to be turned on by a human rather than the exact same time every day and night. Burglars case their targets carefully, and this randomness could scare them away. Install and enjoy!