Installed directly on the wall. When positive pressure is generated inside the duct, the baffle opens automatically.
Valve body thickness: customizable per design requirements (L=50-350mm).
Technical Parameters
| Specification(mm) | Exhaust Air Volume | 1mmH2O | 2mmH2O | 3mmH2O |
| 300 x 200 | 120 | 420 | 600 | |
| 400 x 300 | 150 | 560 | 900 | |
| 500 x 400 | 200 | 630 | 1000 | |
| 600 x 400 | 260 | 900 | 1500 | |