Ah, you get that email, too?

It looks like that might not work as simply as shown. It cuts all four sides of a rectangular hole, so it vibrates left and right while top and bottom keep it from moving up and down, and vibrates up and down while the left and right sides keep it from moving left to right. It cuts all four edges at the same time.

This is still a better idea, though, than all of those flashlights that force you to toggle through a strobe setting to turn the damn thing off. Do you know of anyone who NEEDS a strobe setting on a flashlight, and needs it bad enough that ALL such flashlights have it? (You'd think that if someone needed a flashlight that strobed, the strobe rate would have to be variable.)