Hello, I have had 4 of the 4-inch gray laser pointers - all 4 of their slider-switches failed the same way. I now have three of the 6-inch black/silver-trim ones that have red, green, & blue versions, and the battery contacts are so poorly designed that the operation is frustratingly intermittent. Also they do not stay on: the button must be held. I hope to find a toy that is well designed (that is, one that doesn't fail to operate correctly), and has a switch that stays on. Any recommendations?