aus005 said..I have a few of these they are ok for a cheap yoke i accidentally inflated one when wearing it nearly choked me

Likewise, I accidentally inflated mine when cleaning a bucket of squid, Identical to the one pictured, and it felt like it cut the blood supply to me brain it was so tight!!
I reckon I would have passed out if i didn't get it off and that wasn't easy. Gave me a hell of a fright!