Dear Notch,
If you're designing a hat for women, I think you need to make sure that when you say one size fits most that you mean one size fits most WOMEN. I think that some men would also find this hat too large. I followed the instructions and could not make my prescription glasses fit to the notches either.
I did email about the situation and customer service was excellent but I had already discarded the tags and cardboard so I'm stuck and can't return/exchange. Even if I could exchange, the only thing on offer in a smaller size is the trucker style hats which I don't care for.
All that said, your hat is very well made. A sliding adjuster IS preferable to Velcro when you have long hair so extra points there. I hope in future you can make a line of women's caps to fit women's sizes.