Features: 1.Precision temperature sensing hairspring; Precision wet hairspring; Precision gear transmission structure barometer movement; 1 second precision clock movement; Metal pointer. 2.Readings Comparison: The contrast pin on the lens is used to compare readings to see if atmospheric pressure rises or falls over a certain period of time. 3.Wide Applicability: Generally applicable to ships, factories, laboratories, families. 4.Easy to Install is lightweight and easy to install, suitable for hanging or placed on a surface. Parameter: Material: brass shell, plastic bottom shell, acrylic plastic lens Size(about): thermometer: diameter: 98mm/3.86in, thickness: 33mm/1.30in; hygrometer: diameter: 98mm/3.86in, thickness: 33mm/1.30in; barometer: diameter: 98mm/3.86in, thickness: 36mm/1.42in; timepiece: diameter: 98mm/3.86in, thickness: 32mm/1.26in Dial: 0.3mm aluminum sheet printed black on white. Measurement function parameters: thermometer: -30 ~ 50C, accuracy: +/- 2C; hygrometer: 0 ~ 100% RH, accuracy: +/- 5% RH (40 ~ 70% RH); barometer: 950 ~ 1070hPa, accuracy: +/-5hpa (980~1040hPa); timepiece: travel time error is not more than +/-1 second / day Note: 1.Please allow 1-3mm error due to manual measurement.pls make sure you do not mind before you bid 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package List: 1 *Air pressure gauge 1*Thermometer 1*Moisture meter 1*Timepiece