I had the small one. Put my phone in it (very cheap phone). Had to cross a river, so I made sure everything was sealed, etc. Swam across the river. Phone got wet (not soaking wet). Had to put phone in dry box to make it work again.
I think they (CDR-King) pelican type boxes make good dust-proof, and semi-shock proof cases to protect gear.
I bet some could even be waterproof -- but, consistency of quality would be iffy from unit to unit. So I may have gotten a lemon unit.
Pelican would also have some lemons, I'm sure. Nobody is perfect. But I'd be willing to bet their batting average is CONSIDERABLY higher than CDR-King's.
I think the CDR King is great value for money; just don't expect it to be a Pelican.