Special Features:

Altimeter shall be 3.5"x4.5"x2" dimension or less and weigh 10 oz or less; includes an adjustable strap, up to one ft, such that canbe worn on wristshall be adjustable for the barometri pressure and drop zone altutude; shall consist of a single, durable unit capable of measuring and displaying altitude 25, 000 ft seas level or more with accuracy of 50 ft

Properties:

A barometric type instrument consisting of a pressure-sensitive element which contracts or expands in proportion to atmospheric pressure, connected through a linkage to a pointer. Its dial is graduated in units of linear measurement (feet, meters, etc.) and units of pressure measurement (pounds per square inch, inches of mercury, millibars, etc.) to indicate both atmospheric pressure and differences of elevation.