I've got three here, from when my son went dinghy sailing when he was younger.
Two of them are Gill Marine ones, marked inside 50N BUOYANCY AID EN393. One Large,? 106cm >70 kg. The other is smaller, probably a Medium. It looks to be the same size as the Baltic one below..
The third one is a Baltic, marked 50-70kg 8-11 stone.
?
