Crooked Horn Smoke In A Bottle. 

The Ultimate Windage Detector Keeping the wind in your face is the secret to any successful hunt! Even the slightest breeze can carry your human scent directly to the animals you're hunting. This odorless powder allows you to instantly detect the directional flow of even the slightest air current. Just squeeze the bottle gently and a column of smoke will drift upward from the tip alerting you to any change.