Meet the WoodRiver DIY Kaleidoscope Pen: a neat little kit that comes with everything you need to build a pen kaleidoscope together. You can view through its cap and change the view with a twist of the pen. This pen has a smooth twist mechanism.
More gadgets like this: here
Disclaimer: *Our articles may contain affiliate links. Please read our disclaimer on how we fund this site. As an Amazon Associate, we earn from qualifying purchases.