These have little solar panels that sit on the tops of the lids. They are just barely glued on, and two arrived completely separated from the unit. One I was able to super glue back, and it works, but the other is unusable as one of the wires that connects the panel to the battery pack had severed. I expect that not all pieces in every set will be perfect, but to have 1/3 of a single set arrive actually, physically broken is not worth it. And given the poor glue job, I completely expect this set to not have much longevity.