Novitherm Heat Reflectors fit easily behind most styles of radiators and inside most baseboard convectors, just get a nice rest in with the backrest pillow with arms before installing it. For convectors, the covers are removed and the Novitherm Heat Reflector is affixed to the flat surface at the back of the convector. Convector installation requires a space of 1/3″ (1 cm), behind the heating fins. Novitherm Heat Reflectors fit easily behind radiators provided there is a gap of 3/4″ (2cm) or more.