Porch awning for my Lunar Quasar

Orior

Just bought my first caravan and a friend has offered to sell me an almost new porch awning. Before I show any interest, is there anything I should be aware of about porch awnings in general? Are they specific to particular caravans? I gather that they are
sealed to the caravan walls by foam wrapped poles. As different caravans have different window/ventiilation grille positions, how do I check if this could be a problem before expressing an interest. It could be awkward to say no after a trial fit.