1100% brand new and high quality. 2The instrument is for measuring differential pressure, positive pressure and nagative pressure 3It can be used to measure air-conditioning and ventilation system or verify in the site, and clean room or any corrective maintenance of gas pressure system. 4Simply operation and convenient to carry. 5It is a indispensable measuring apparatus to heating and ventilation air-conditioning technicians, operating maintenance engineers, and scientific researchers.Features: 1.100% brand new and high quality. 2.The instrument is for measuring differential pressure, positive pressure and nagative pressure 3.It can be used to measure air-conditioning and ventilation system or verify in the site, and clean room or any corrective maintenance of gas pressure system. 4.Simply operation and convenient to carry. 5.It is a indispensable measuring apparatus to heating and ventilation air-conditioning technicians, operating maintenance engineers, and scientific researchers. Specification: Condition: 100% Brand New Model:SW-512B Range of Measurement: 39.99kpa Accuracy: 1%FS Maximum Limit of Pressure: 79.9KPa Repeatability: 0.25%FS Pressure Connection: One 1/8''(3.18mm) Quick Coupling Operating Temperature/Humidity: 0-40 10%-80%RH Storage Temperature/Humidity: -10-60 10%-90%RH Outrange Warning: Err1 Or Err2 Power Supply: 3 x 1.5V AAA(not included) Weight: Approx. 341g / 12.0oz Package List: 1 x Digital Differential Pressure Gauge 1 x User Manual 1 x Pressure Head 4 x Transparent Tube 1 x Carrying Bag