Product review (5 stars): Nothings worse than a flimsy unit tweaking and hindering the flap
The 639 Broan Wall Cap is ideal for through the Wall venting of over Range Microwaves. The gauge of Metal and Construction quality exceeds most 'Big Box offerings. Nothings worse than a flimsy unit tweaking and hindering the flap. This flap does not rattle with air flow and shuts quietly when u shut Fan off.