HVAC / R air conditioning refrigeration industry used to measure pressure difference. facilities. Measuring negative pressure setting to indoor air will not pollute the air in the outside world. Measure positive pressure. Peripheral Pneumatic Control Equipment. Maximum / Minimum / Average Read Write Function. Large backlit LCD dual display. Reset, offset and data offset. Set the low battery display and auto power off function. Data Retention and Error Code Functions. Over / Under Indicator Range. The user can re-calibrate the meter at any time. Pressure Range: + 2psi Accuracy: + 0.3% (at 25 Celsius) Repeatability: + 0.2% (Max + 0.5% ) Linearity / Hysteresis: + 0.29% Response Time: 0.5 Seconds Above Display Range Indicator: Hi Under Display Range Indicator: Lo Operating Conditions: 0-50 Celsius (32-122 Fahrenheit) Storage Conditions: -10-60 Celsius (14-140 Fahrenheit) Power Supply: 9V Battery Color: black Material: ABS Size: 150*55*40mm Package Contents: 1 * Digital Manometer(without battery) 2 * Plastic Hose 1 * Metal Connector 1 * Carry Pouch Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.