I got 2!!!!
The 1st I got was a black lightweight 'arm' but I found it only lit centre of page and outer edges were still quite dark for reading.?
2nd was a silver/grey 'robotic arm' type that still attaches to back of Kindle but light seems to spread more evenly over page and it's brighter in general too.

Got both from ebay ...about £2.99 each.

christine xxx