We chose these because they cost less to buy in bulk than others I saw. We handed them out at a Trunk-or-Treat so can't say if a percent didn't glow - but all the ones I saw activated did. I don't know how long they all stayed glowing, but the one I used glowed brightly for 5 hours, and still had a faint glow after another 5. One comment, for what it's worth: some of the sticks are clear - they do glow when activated, but younger kids were pretty suspicious and wanted a 2nd one or to trade the clear for a better color.
I wanted some glow sticks for when we went to Disney this year. I had them shipped to the house we were staying at since we weren't checking any bags on the plane. These worked great. We had a 1.5 and 2.5 year old that just loved them. They were bright and lasted a fairly long time before losing any vibrancy. They are about pencil thin so not overly big and long enough to fit around my wrist. Too long to fit snugly around a toddlers wrist though, though the girls didn't seem interested in wearing them. I would definitely recommend these and plan on using them as party favors for my daughters next birthday. What bigger hit is there than glow sticks.
hey were bright, very visible and seen at a distance, lasted all night. You will be very happy with your purchase.