Double air outelt with adjustable aluminium louvre (anodized) for optimal air flow.Inlet grille is in matching colour of the device, made of perforated plate for filterless and easy to maintain operation. Energy-saving double-jet door air curtain with or without heating. Only two- thirds of heating power will be required compared to standard air curtains. Sound- and heat- dampening internal insulation.Anti vibration mounted and separately driven centifugal fans with thermostat relays for motor protection. High efficiency heat exchanger for low temperature heating, made of copper tube with integrally moulded aluminium vanes. Threaded hole M8 for ceiling mounting. For energy saving reasons, a themostatic 2- way or 3- way valve can be ordered to keep the intake air temperature on an even level. It is delivered loose and can be fitted.