Could you please confirm dimensions of the back panel - i.e. what insert size does it fit? I have a 475W x 600H (mm) insert. Would that work?

Hi, thanks for your enquiry. The back panel we supply measures 37" x 37" and has a pre-cut opening of 16" x 22" (406.4mm x 558.8)mm which is suitable for most standard gas and electric fires.