Family Handyman online did a “Stuff We love” segment that includes a Smoke Pencil review video:

Smoke Pencil video

https://cdn.jwplayer.com/previews/O3dBHSzv

This informative Smoke Pencil review video takes a close look at a number of tools and solutions to tighten up the energy envelope of your home.

The Smoke Pencil is a very effective and simple to use diagnostic tool. It is effectively a hand held fog machine. You pull the trigger to get a trail of smoke, or pump the trigger to get a puff of vapor, so you can see drafts and air currents. As you can see int he Family Handyman Smoke Pencil review video, you would use the vapor to test around obvious leak points, like windows, doors, fireplaces, and outlets. But you may be surprised by finding lek points in unexpected areas like under cabinets, or near soffits, or basement rim joists.