Review on Amokeoo Smart Watch: Fitness Tracker with Heart Rate & Blood Pressure Monitor, IP67 Waterproof Bluetooth Android Smartwatch, Touch Screen Sports Watch for Android and iOS Phones - Men Women Black by David Edwards

These lights are only $10 so don't expect them to be fantastic but they are actually quite bright and very easy to hang on the wall with pins. One of the lights blew out before I plugged it in, but they offer a couple of spare bulbs (although I have yet to replace them). The measurement is fairly accurate for 20 feet, but you may need an extension cord if you're plugging the lights into the ceiling and don't want them illuminating the wall. Not sure about longevity as I've only been wearing it for a few days, but I can also say that this color is good at night and doesn't hurt my eyes.