I bought this water purifying straw at a garage sale for 50 cents. It is new in the package but it does seem to be quite old. The woman selling it said that they don't expire and this should still be fine. I couldn't find any info on this exact item online

What do you guys think? I plan on using it on my trip up to Half Dome.

-can the water going through this be trusted?
-do these things expire?

thank you