Manometer Gas Pressure Tester, Digital Manometer Dual-Port Air Pressure Meter with Backlight and Data Record Function, Manometer HAVC with 12 Measure Units

I Used this to measure the pressure drop inside my house whenever I turn on my blower fan and it reads very accurately and no calibration needed and it shows in any unit you want. Furthermore, i also records the max value which is very usefull

My box only came with one tube and fitting, whereas the photos shows two of each. That being said, it is a good little tool that works pretty well!

Hose ports were to small for my needs.

Its a cheap unit, but works ok. The hoses are so small, they work ok with the provided adapter but will be more difficult to use otherwise.