This is an excellent little light. Even on the lower power setting it is bright enough to read my Kindle in bed at night. It is quite light weight and trim, so it effectively adds almost no weight to my Kindle or even a book. Additionally, the battery lasts quite a long time, especially with the lower brightness setting.

The "clip" does have a certain range or thickness it can work with. I have a folding cover over my Kindle. I found this item worked best when my Kindle cover was folded open and I attached the clip over both the front and back covers, but just behind (or above) my device itself. This did mean that I had to detach it each time I shutdown my Kindle in order to close the front cover, but it has worked well.

As the device requires a minimum of about 1 cm or 5/16 inch of thickness to hold it in place, it was a little harder to find a good way to attach it to a hard cover book (I did not try a paperback), but I was able to carefully attach it over the back cover and a thickness of unread pages adjacent to the back cover. When I reached the last parts of the book and needed to read the pages, I simply moved the light over to the front cover with a portion of the adjacent and already read pages to make the thickness needed to hold the light in place. So, not a big problem as a work around.

Overall, I really love this little light. It is better than a previous type I owned as this light does, indeed, illuminate the entire page and has a longer arcing neck to position the light where you desire. I have owned this for a few months, use it every night for a hour or so, and so far so good and no battery change yet needed.

Stop paying crazy prices so that your books only Kindle may have a small backlit screen to aid in your quest to read anything, anywhere, anytime. Despite the light levels available in your surroundings. Additional light sources and/or a Kindle Paperwhite are now rendered obsolete.....ALL OVER AGAIN! Just like when I picked up my first e-reader (NOOK :)) and bought something exactly like this.

The lamp is lightweight with over 75% of its weight coming from the 3xAAA batteries it requires. Once they're inserted, you're off to the races!

The lamp fits nicely on my OG Kindle reader (ver. 2. pre paperwhites) although it did tend to slide around here and there. The bulb has three unique settings you can use. An ultra bright, a really bright and a standard....bright. The only issue I encountered was a small glare on the screen from the more visible center circle of the screen. I had the lamp twisted and tilted a few different ways until I was able to eliminate the glare and bask in the technology of 2005, a week and a half ago under the stars while hiking.

My only gripes are in the not exact fitting clip and the perhaps a bit TOO bright bulb itself.

Otherwise, this device is sturdy. It sat, squished into a front pocket on my hiking pack for the first two days, enduring a half day of thunderstorms along the way. I thought it would be toast by the time I went to use it. After taking the battery cover and batteries out for a few hours and letting it dry out, it worked like a charm though. I would say it is moderately water proof, as EVERYTHING else in that pack was waterlogged and worse for wear.

I bought this light for my Kindle keyboard because I broke the cover light and couldn't find a replacement. Overall this is a good light- it seems sturdy, I like how flexible the arm is so you can angle it in any direction and it isn't intrusive on my reading screen.
There are 2 things that caused me to rate it 4 stars (more like 3.5) instead of 5.

1- there are 2 light brightness settings (which is nice) however the light is either really bright or really really bright. On a good note, if you're looking for a really bright light, this is it. For me, I read in bed so I don't need an overly bright light, it's almost hard on my eyes and reflects on my no-glare screen. Because the arm is so flexible, I get around the brightness issue by angling it past the top of my screen instead of down onto the screen-not ideal but workable.
2- My only other issue is that it is not snug on the kindle keyboard model so if your reader is thicker than this model it should be a non-issue for you. It does hold somewhat due to the rubber cushioning but if I turn a certain way it will occasionally tip off the top. Again, not terrible or a deal breaker, just wish it fit my specific reader better.

Again, well constructed and good design and has proven to be very durable. I could see this being a great light for someone looking for a bright light with a slightly thicker reader model.
UPDATE: I am changing my rating to 5 stars because while everything I said above is still true, I have used the light for other things and have found it REALLY useful and the batteries last forever. I also just purchased 2 more for my 6 and 8 year olds because they love to read in bed and it fits perfectly onto the slats of their headboard. The brightness of the light is perfect for them since it isn't being clipped right onto their book and its about 18 inches away and still gives them plenty of light. It's also nice that they don't have to get out of bed to turn a light off.
Very happy with this product!

I noticed some reviews remarked on how the light was still too bright on the lowest setting.
The following is for tinkers or those who dare to live on the wild side and void warranties (it's a $15 light and no harm will come to it.):
To solve this take a 6-8 inch strip of aluminum foil, then fold it (long ways) the height of a AAA battery PLUS about 1/16th inch higher (aprox. 2mm). Roll that aluminum "battery" up into the rough shape of a AAA battery. Put the aluminum "battery" in one of the two slots and place two real batteries in the other slots. Still too bright? Make another aluminum "battery" and run the contraption on just one real battery. P.S. Also works on remote controls.

The iKross seems to give off more light then what I have been using since I purchased my Kindle several years ago. That light just wasn't doing what I needed it to do. This is actually my third light and it seems to work just fine for my needs. It does not have a clip with a spring, it kind of just slips onto either the Kindle or my cover. It fits perfectly over my kindle but I have a cover. It fits over the back and front of my cover when my cover is folded over to the back. It is too loose to fit only on one side of my cover but after trying out different positions I finally found the right one that is most comfortable. It also lights up the entire page unlike my other one that kind of lacks lighting towards the bottom of the page. I would recommend this light to other people with E-Readers.