THM90 is a flat, made of aluminum, flap diffuser, equipped with a thermal break, designed for aluminum, wood and PVC windows. The THM90 diffuser is a new, improved version of the TH90 diffuser. Built-in wind flap guarantees high resistance to water penetration even in the open position. The use of a perforated external profile provides protection against insects, and the simplicity of construction makes it easier to keep clean. This diffuser can be mounted either under the glazing (PB version) or between profiles (TR version), which allows it to be used as a ventilation for winter gardens.