Just got my cowl in the mail!!
The back of the cowl has a large strip of neoprene with zippers on either side, the pieces attached to the back are plastic.
The head does seem a little small. I was afraid to try it on because I didn't want to get it stuck.
Update: I have since tried on the cowl after measuring the head that it came on. The head is about 23" and there is a little wiggle room. My head is about 23-23.5". It fits great there is even a little bit of wiggle room when wearing it, but not too much. If you have a 23-24 inch head, it will probably fit you just fine.
I ordered one two months ago. Seller has stopped responding. I understand the delays related to COVID-19 situation but I can only send so many emails that don't get a reply before I have to escalate things.