Not to be mean, but most of the "DOA" are NOT really "DOA!!!" The science behind these doesn't any easier than batteries, two contact points, and an LED. Most if not ALL of the "DOA's" just need to be taken apart and have the SHORTER of the two contact pins from the LED slightly adjusted! Pain in the butt I know, BUT we're not exactly paying top dollar for a hi-tech computer system sending men to Mars! Just make sure you put a piece of clear tape around the back end after putting it back together (CAREFULLY taking it apart).
I have purchased these before and am about to get another 2 or 3 sets of 40 because the kids just LOVE them! I will be giving the 4-packs to kids my 8 y/o girls softball team and boys 8 y/o boys hardball team!
The BEST usage and effect??? You want YOUR kid to be the TOTAL ENVY of every kid in the neighborhood ??? Stagger a red, white, and blue one on the spokes of both tires on their bikes!!! Simply unloop the rubber band and slide a Zip-Tie throught the slot and anchor them to the spokes! At dusk/dark they can simply flick the buttons on them ... AND BELIEVE ME .. IT REALLLLLLY LOOKS COOL as they streak down the street.... and the kids TOTALLY FREAK OUT!!!!
Besides .... 10000000x better than reflectors! Just make sure they/you turn them off when they come in to save battery life!
MINE LOVE IT!!!