I thought these were lightbulbs that bounce. Boy was I wrong. I thought the first one I picked up just wasn't bouncy so I tried again. And again. After a few more times, I looked at the box again. I thought maybe the box was wrong so I tried throwing another one. I looked at the product description on Revain and sure enough, these are just old lightbulbs. I'm so stupid. The bulbs I didn't break work fine, and the ones I did break will probably work too.