PRESSURE GAUGE.MEASURING RANGE: ±2 CM/COLUMN H2O.BRAND – B: DWYER MAGNEHELIC.MODEL – B: 2300-4CM.PART NUMBER – B: 2300-4CM.MEASUREMENT: DIFFERENTIAL.TYPE OF CONNECTION: 1/8” NPT THREAD.DEGREE OF MECHANICAL PROTECTION: IP 65..DIAL DIAMETER 4.3/4@ (12 0.65MM),.RANGE (+/-)2 CM OF WATER. LINEAR SCALE, SUCCESSION OF GRADUATION MARKS AND POINTER MARKS IN UNALTERABLE BLACK ACCORDING TO STANDARD EN 837-1.PRESSURE RIM AND CASE IN BLACK PLASTIC.OVERPRESSURE LIMIT: 1.3 X FULL SCALE.ALUMINUM ALLOY DIAL WHITE BACKGROUND ACCORDING TO STANDARD EN 837-6.ACCURACY (+/-) 2% TO FULL SCALE.SEE ATTACHED DOCUMENT.