Feature:1. Professional Manometer: it can test the differential pressure of areas and pipes, wind velocity of pipeline. It has wide pressure range and +/-0.1% accuracy.2. Clear Display: 2.7-inch LCD screen with backlight display for easy reading.3. 12 Selections of Measuring Unit: hpa, kpa, mmHg, psi, mbar, bar, ozin2, inHg, Kgcm2, inH2O, ftH2o, cmH2O.4. Other Features: Max./Min. value measurement function, data record, data hold and zero function.5. User-friendly Prompt: low battery indication, Hi and Lo over range indicator.Specification:Features:Professional Manometer: it can test the differential pressure of areas and pipes, wind velocity of pipeline. It has wide pressure range and +/-0.1% accuracy.Clear Display: 2.7-inch LCD screen with backlight display for easy reading.12 Selections of Measuring Unit: hpa, kpa, mmHg, psi, mbar, bar, ozin2, inHg, Kgcm2, inH2O, ftH2o, cmH2O.Other Features: Max./Min. value measurement function, data record, data hold and zero function.User-friendly Prompt: low battery indication, Hi and Lo over range indicator.Low Power Consumption & Power Saving: powered by 3pcs AAA batteries(NOT included), and it will automatic power off after no operation for 15 minutes.Compact Size & Lightweight: easy to operate and carry, it also comes with a protective zipper pouch.Wide Applications: applied on chemical industry, electrical industry, nuclear industry to measure the difference of air pressure, etcSpecifications:Model: AS511 / AS511B (Optional)AS511: Differential Pressure Measuring Range: -39.98~39.98KPa Maximum Permanent Load Pressure Range: -79.96~79.96KPa Pressure Resolution: 0.01KPa Accuracy: ±1%FS, maximum error: ±400PaAS511B: Differential Pressure Measuring Range: -206.8~206.8KPa Maximum Permanent Load Pressure Range: -413.6~413.6KPa Pressure Resolution: 0.1KPa Accuracy: ±1%FS, maximum error: ±2.08KPaMeasurement Selection Rate: 0.5 secondsUnit: hpa, kpa, mmHg, psi, mbar, bar, ozin2, inHg, Kgcm2, inH2O, ftH2o, cmH2OTemperature Measurement Range: -10~60Humidity Measuring Range: 5~99%RHTemperature Accuracy: ±2Humidity Accuracy: ±5%RHStorage Environment: -10~70 / -4~140Power Supply: 3 * 1.5V AAA battery (NOT included)Material: ABSItem Size: 167 * 65 * 30mm / 6.57 * 2.56 * 1.18inItem Weight: 141g / 4.99ozPackage Weight: 305g / 10.77ozPackage Size: 24.8 * 9.3 * 5.3cm / 9.76 * 3.66 * 2.09inPackage List:1 * Manometer1 * Package of Accessory2 * Plastic Pipe1 * Zipper Pouch1 * Manual(English)Package List:1 * Manometer1 * Package of Accessory2 * Plastic Pipe1 * Zipper Pouch1 * Manual(English)