The SteriPEN

There are a number of ways to purify water.  Most rely on a form of filtration or the use of chemicals.  The SteriPEN takes it in another direction, using light.  The SteriPEN uses ultraviolet light to, wait for it, sterilize the water...  The light actually destroys the ability of microorganisms to reproduce, and therefore get you sick.  (At least 99.9% of them anyway)  Mind you this does nothing for taste or particles, and there is the issue of batteries.  But it may be a good fit depending on your needs.

You can go here to pick up the SteriPEN: https://amzn.to/3GpztGw

You can find the PDF with all the Light Codes here: https://kitbadger.com/wp-content/uploads/2016/10/classic-user-guide-en.pdf