Linear Slot Diffuser

Those are called slot diffusers As shophound said, linear slots look nice but they need to be designed and installed correctly

Slot diffusers for wall installation, with adjustable air control elements Can be combined with PURELINE18, PURELINE35 und PURELINE50 diffuser faces

slot william hill trucchi Linear slot diffusers model MLC are designed for variable air volume systems They ensure a uniform blanket of air that adheres to ceiling even at low flow

66 slot Linear slot diffusers Foam gasket is sealed around the back of the frame as option to avoid air leakage Suitable for installation for ceiling and sills