Review on Enhanced Klean Kanteen Sport Cap 3.0 Replacement Cap: Upgraded Functionality and Durability by Erica Gutierrez

I prefer spouts that open and close like this on our children's water bottles because they are easier to drink and avoid spills. But that rubber tip will trap debris underneath and inside, resulting in messy mold. We've only ever used them to drink water, so any particles that get in there are solely from toddler backwashing. I've tried washing dishes, washing my hands, soaking in apple cider vinegar, scratching with a bobby pin to no avail! Within 6 months they are not good. Too bad because we love this company!