Or if you want to be sure you’re getting something decent, go with RMM mtnelectronics for $5.39
and avoid the inevitable surprises and frustration of the china lottery experience.
http://www.mtnelectronics.com/index.php?route=product/product&path=80&product_id=319
or for less sharp edges, this one: Review: Ultrafire zoomie from Banggood
But actually I’d agree with Power above’s second link — look it up as the “#3 zoomie” — that is a good choice, if you put the money you save into putting an Energizer Lithium primary with each of them.
That way the kids will get a long-lasting light and it won’t dissolve into crap like the alkalines inevitably will.
Thing about LED lights is — they’re still shining brightly while the alkaline leakage is already starting, so kids don’t check and find the problem.
With incandescent emitters, the battery would go low and the light visibly dim, usually before the alkaline leak started, so it would get noticed.