Review on 🔧 Orion Motor Tech 3-Way AC Gauges Manifold Gauge Set for Freon Charging - Fits R134A R12 R22 R502 Refrigerants, with 5FT Hoses, Adjustable Couplers, and Can Tap by Dave Goodman

I am a professional HVAC technician and have several high-end professional sensors. I got this for a friend who I teach work to. This will work for a beginner. The problem is that the bottom arrow is offset by 3 dots, it should be at 0 not 3. So when I try to calibrate it back to 0 the pan head screw is locked on the screen I try my best. to turn it and it's just blocked.