Niagara Air Filter Whistle

The Niagara Air Filter Whistle lets you know when it is time to change the filter in your furnace or central air conditioner, helping it run more efficiently and saving energy.  How does it work? As debris accumulates on your filter, more air is forced through the filter whistle, eventually resulting in a steady, audible whistle to remind you that the filter needs to be changed.

• Snap the two-part plastic device onto your filter to install
• No tools required to install