External louvres include variants from small to large sizes with both circular and rectangular openings. Small external louvres are used as covering grilles in air supply and exhaust openings. RIS is an external weather louvre of robust design for air intake and discharge.

	EYMA-2 is an exhaust air diffuser whose special design prevents rainwater from entering the duct. EYMA exhausts air straight up at a high velocity, protecting the diffuser against settling dust and other impurities preventing the warm exhaust air from melting snow around the diffuser.
	DYMA-1 air intake device is designed to bring fresh air into the ventilation system, while keeping the air flow velocity outside the device low enough to prevent rain water from entering the system.
	US-AV External louvres are used as covering grilles in circular air supply and exhaust openings.
	US-VN External louvres are used as covering grilles in rectangular air supply and exhaust openings.
	US-SV External louvres are used as covering grilles in circular air supply and exhaust openings.
	SVN External louvres are used as covering grilles in rectangular air supply and exhaust openings.
	RIS External weather louvre of robust design for air intake.
	RISJ External weather louvre of robust design for air discharge.
	RISD Circular external weather louvre of robust design for air intake.