Originally Posted by
joshliu22
The problem with UV design is it must be used in a stainless steel bottle for it to work properly, which is one of the downsides, so it wouldn't be possible to design it for a Nalgene bottle.

The UV water treatment devices currently on the market claim to work in glass or plastic, and Steripen's pre-filter/attachment is actually threaded for a 1L Nalgene bottle (though it's not particularly convenient to use).