Bests & Worsts Reviews from Amazon

This GravityLight is a unique and interesting device, which provides a (bright) booklight's worth of lighting. This may seem like a small amount of brightness, but it is WAY better than the alternative of total darkness when you need light. When I tested this in total darkness, it felt quite bright- light enough to find your way to the bathroom, for example, or to chat w your buddies at your campsite and see their faces. The device is comprised of a "head" portion that has one LED bulb in it, a bunch of beaded pulleys w a counterweight, and a separate nylon sack that opens upward on two sides (each side has a pull closure), which you fill w any type of heavy object (rocks, sand, dirt, etc...), to equal a maximum weight of 25lbs. The set comes with 14 small paper bags to facilitate your adding rocks, dirt, or sand into the larger nylon sack more conveniently. You're supposed to add enough of the filled/weighted paper bags into your nylon hanging sack until you see a red light shine- at that point, you remove material until you see the regular white light. I tried this on a pull-up bar on my bathroom door, and used barbell weights to add exactly 25 lbs. The white light turned on immediately. I took out weights, and found that the white light stayed on even with approx.14 lbs in the bag, but the LED was dimmer. On the other hand, less weights meant the bag descended more slowly. The more weight, the more light, but the quicker it goes out. To use the device, you raise up the weighted nylon sack by pulling on one side of the orange cord (like a curtain shade adjuster). There is only one orange colored cord among a bunch of black cords, so i'ts not hard to find, and it's also not difficult to pull the 25lb sack up in this manner. As the sack slowly descends via gravity, it feeds the LED energy. This set also provides two separate mini-lanterns and 2 long cords, which you can hook to the "head" and then to each other, to make a string of 2 lantern lights (when the 2 lanterns are in use, the main head lamp does not turn on). This allows you to split the lighting, and to have the option to place lights closer to where you need them. Each of the 2 lanterns can be adjusted by twisting, for three separate lighting levels, so if you plug them in and they don't turn on, try twisting to turn them on. The two lanterns together at their highest levels are about the same brightness as the main headlamp. Overall, I found this device to be a novelty and pretty cool as a concept, but a bit cumbersome in use- it's a testament to the good design that the cords on this device don't get tangled up, considering how many there are, and how closely they are placed together. On the other hand, you still just have a ton of cords, and it looks very messy and takes up a lot of space...and there's no way i'm taking this hiking. It'd be great for car camping though. I have solar lanterns that weight a few oz and run for 10 hours with 10 times the light as this GravityLIght. But, they still need sunlight and hours to charge. This GravityLight works instantly, and can be a lifesaver if you truly are out of options- no batteries, no wind-ups, no solar, no candles, no fire... this also overcomes the obvious and significant disadvantage of using up a non-renewable energy source, and then being SOL. So, I'd say this is good to have for your tool kit of available lighting options, either at a campsite, for emergency planning, or just as a conversation piece showcasing the clever engineering.