Made by Jules Jurgensen, makers of fine timepieces since 1740, this rugged watch is the same one used by aviators as an aid for navigation. Its bezel has a built-in compass that provides bearings in 10-degree increments. The rotary slide rule permits rapid calculations and conversions, allowing you to multiply, divide, and calculate fuel consumption rate, distance and speed, and convert between kilometers, nautical, and statute miles. It converts U.S. gallons to liters and fuel pounds to U.S. and Imperial gallons, and it has a built-in chronograph (with countdown timer) that displays lap time, splits, and total time. Its quartz movement watchface provides accurate timekeeping during day or night, and it has luminescent hands and numbers, pl us month and day digital display. It is waterproof down to 165' and adjusts for multiple time zones. Battery included. 1 1/4" Diam. (8 oz.)