The square steel swirl diffuser with adjustable plastic drums type WT350 is used for the supply of cooled or heated air in facilities such as offices, shopping centres, schools, … Suitable for ceiling or exposed duct mounting. The diffuser is equipped with adjustable ABS deflectors creating the possibility to obtain an external or internal swirl. A high induction is obtained by the exceptional swirl discharge, which makes them extremely suitable for VAV terminal boxes. The plenum WP350S is designed in a pyramid shape in order to make it stackable and allow easy economical transport.