Reviewed by DKowner from coastal New England on Monday, March 20, 2017
Good to have in case of an emergency. These work well (I know from experience) and are easy to use. Compared to a mechanical filter (my preferred purification method) these take up next to no space and no maintenance is needed. Yes, there's a bit of an aftertaste from the chlorine but it's better than catching giardia! The package I received was marked with an expiration date of 5/2021.