Waterproof and you could run over it with a car without damaging it.
It is expensive but the last pill holder you will ever need to buy unless it's stolen or you lose it. Tip after reading few reviews complaining about pill tables being damaged in the holder. I have always packed, (place tablet pills in small piece of paper towel or cotton ball),  any tablets even in plastic pill bottles I travel with or place in pocket. I have never had an issue with damaged pill tablets using this method.
Rating: 5 stars