Sawyer Water Filter S1:

The next generation of highly functional water filters is the Sawyer Select series. It starts with the number 1, which is this model. Unlike other filters, which for most people cover a basic need to filter out bacteria, this one also removes chemicals and pesticides. Other filters outside the S-series do not do that!

Avoid Upset Stomach

Like other Sawyer water filters, this one protects you from stomach issues:

Removes 99.99999% of all bacteria, such as salmonella, cholera, and E. coli, and removes 99.9999% of all protozoa (such as giardia and cryptosporidium)

Chemicals + Pesticides... the Extra Safety

If you take water from a ditch or stream, it can easily contain chemicals and pesticides from fields in Denmark. The S1 filter handles that.