what is the sizing for a medium or large hat? Is this hat crush proof and packable?
I can't address the size question b/c I don't quite understand it. Mine fits well. I need a large and it is comfortable. I keep mine in a backpack pouch that doubles as a fanny pack, so I fold it twice. I would not place it under something with a lot of pressure on it, but when I take it out of the pouch it returns to its original shape. And it is definitely waterproof. It was a lifesaver during a rugged trip through the Philmont Scout Ranch in NM last summer. Really glad I had it. The wide rim is excellent at keeping the water away from your neck!!
I am not very familiar with hat sizing. I purchased this hat in XL and I am very pleased with it. I usually wear a size large, but this hat was adjustable so I took the risk. After adjusting the inner velcro band, the hat fit great. It is also packable and crushproof and easily returns to its normal shape. It has a semi rigid brim that is great for keeping the rain from running down your neck. Although it is not goretex, it does repel water and after getting caught in a downpour, there was no evidence of any saturation. As far as I'm concerned, this is a terrific hat for the price.
I purchased a medium hat, but they are quite adjustable. Normally I wear a small, and this hat adjusts to fit just fine. I wouldn't call it crush proof, but if you pack it flat it would be ok. Haven't actually tried crushing it.