Has it got anything stamped on it? If not, doesn't necessarily mean it's no good and if it's just going to be used for ad-hoc self-recovery then you're probably fairly safe.
It's described as 'heavy duty swivel hook and G10 G link'. Googling I've found that it is a Gunnebo Johnson G link used for joining chains etc. I wasn't sure if swivel hooks are OK, but there also seem to be lots or winch ropes sold with them fitted.