Barometer having sensitive and accurate movement with 100mm circular dial graduated 28 to 31 inch of mercury and 960 to 1060 × 1hPa. The scale designed for maximum clarity and ease of reading completely enclosed in a transparent plastic case with movements clearly visible for the demonstration of its working. With resettable index pointer. Actual effect of increasing or decreasing pressure can be observed as air pressure is changed by squeezing and releasing the attached pressure air bulb