I ordered 250 of these lights. 93 of them did not work. Although 4-imprint prompltly sent 93 replacements, 16 of those did not work. Curious as to why they did not work, I opened them up. The contact for one of the batteries was badly corroded in most of the lights. It appears that the lights were packaged with moisture in them. While the kids love this item is not worth the trouble.