Review on Contigo Autoseal Trekker Kids Water Bottle, 2-Pack: Granny Smith & Nautical - Perfect Hydration for Active Kids! by Jason Sundstrom

We love these mugs! Unfortunately we had a mold problem and had to throw it away and now I'm guessing. The small drinking hole has a silicone backing that seals it when closed. We clean the cups regularly and always use ONLY water, but one cup went missing for a few days and when it came back there was mold on that silicone piece. I tried my best to clean it, washed it in the dishwasher and even bleached it, but the mold got stuck. There is not enough space to clean it well. We checked the other one we had and it also had quite a bit of mold - not as noticeable as this one and that's probably why it didn't show up during routine cleaning. If we buy more I will do a more thorough cleaning and maybe a regular bleach.