Vauxhall Cavalier mk3, f-j (possibly early k) reg. You need to remember they are upside down on the Griff so an o/s Cavlaier light is a n/s Griff unit. FFG
There are i think 3 different colour variations, thought they all have the same dimensions, so if you're only buying 1 look carefully to be sure you match it to your existing other light.
Normal ones are clear, the GSi ones are smoked and rarer, hence more expensive. Just be careful not to get the later lights (K reg and later I think) as they are not flat and have some bumps on them FFG