They had 2 big boxes of these light at Sainsburys in Grantham, now they only have 1 box of them left... ;)
The waterproof, shockproof version works up to a depth of 2m and its sturdy rubber housing will also float. Three extra bright LEDs are powered by three AAA batteries. It comes with a sucker, sticky attachment and is also magnetic- ideal for camping, and even cheaper than just buying batteries!!!