An ideal solution to eliminate cold drafts from leaky shutters. Mounts over shutter on inside of building. Air flow created by fan draws lid open, lid closes tight when fan not in use. Constructed out of polyethylene, fully insulated to prevent freezing.
- Model No. BD-1220
26" square opening for 12" - 20" fans
- Model No. BD-2428
26" square opening for 24" - 28" fans