I picked this up at an estate. See pictures it powers up but that is the extent of testing.Please ask questions if needed. I don't have a vent in my apartment to test but I did put the hood over a fan both front and back. I got readings from both sides. 270 front/supply and 119 back/exhaust. The item "Alnor Electronic Balometer with APM 150 meter Air Flow Capture Hood with case" is in sale since Wednesday, May 23, 2018. This item is in the category "Business & Industrial\Electrical & Test Equipment\Test, Measurement & Inspection\Test Meters & Detectors\Other Test Meters & Detectors". The seller is "rochellenecole2010" and is located in Windsor, Connecticut. This item can be shipped to United States, Canada, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, Sweden, South Korea, Indonesia, Taiwan, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Israel, New Zealand, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Kuwait, Bahrain, Croatia, Malaysia, Chile, Colombia, Costa rica, Panama, Trinidad and tobago, Guatemala, Honduras, Jamaica.