I have bought my son several boots from REI. He has a pair that still fits. But I know that in the past I have bought him waterproof and boots that are not waterproof. I don't have the box anymore. How can I tell if the boots are waterproof or not? The boots he has are Moab and the number on the inside label is J06045
@BSA1 Thanks for reaching out!
Generally speaking, if a hiking boot is designed with a waterproof/breathable fabric (like GoreTex) there will be a small tag somewhere on the boot indicating that it is waterproof. The Merrell Moab comes in a waterproof and a non-waterproof style. We have included a photo below of the indicator that it is waterproof, for reference. If your son's boot does not have this tag, it is likely not designed to be waterproof/breathable.
Hopefully this helps!