This is a Dwyer magnehelic differential Pressure Gauge Model 2010 AV with duel scales 0-10" w.c. and 2000- 12500 FPM. It's 5" in diameter , has a low and high intake ports. This particular gauge is a little dusty because the box has disappeared. It has some very light scuffing on the cover lens,barely noticeable. Never been used. Thanks..Enjoy
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