Vallox 245 MV R model in the figure. In the L model, the parts are mirrored. 2a Heat recovery cell 2 kpl 3a Extract air fan 3c Supply air fan 4a Fine filter for supply air 4b Coarse filter for supply air 4c Coarse filter for extract air 5a Bypass damper of the HR cell 6a Post-heating resistor (in the supply air duct) 6d Post-heating liquid radiator (245 MV VKL) 7a Safety switch 9a Ceiling bushing for electric wires 10a 10b Control panel 11a Internal humidity sensor (behind the electric box) Internal carbon dioxide sensor (behind the electric box) 11c Carbon dioxide sensor (optional) 11d Humidity sensor (optional) 11e VOC sensor (optional)