Review on Wintact Handheld Anemometer Water Resistant, Small Digital Wind Speed Meter Gauge, Pocket Air Flow Tester With Measuring Wind Temperature 14℉ To 113℉ For House HVAC Outdoor Kite Boat Sailing Surfing by Mike Rogers

My son is a HVAC tech and needed one of these so he quit borrowing everyone else's. It didn't come with any type of directions or manual, but he was able to figure it out on his own. The first thing you have to do is insert the battery (which it comes with, thankfully), so you remove the skin and use a coin to get the cover removed. He was able to turn it on, and use the toggles to test it with what seemed like good accuracy. He's excited he no longer has to borrow from the "big boys."