The Hamilton Khaki Aviation Converter Auto Chrono (44mm, Black Dial) is a high-performance pilot's watch designed for advanced aviation calculations and refined utility. Driven by a premium Swiss automatic movement, its signature feature is a bidirectional slide-rule bezel designed to calculate critical flight metrics and unit conversions on the fly.

• Movement: Hamilton H-21-Si automatic chronograph caliber (based on the legendary Valjoux 7750). It features an antimagnetic silicon balance spring and a 60-hour power reserve. 

• Case Dimensions: 44mm diameter, 14.6mm thickness, and a 54.1mm lug-to-lug distance. 

• Dial: Matte black with charcoal/smoke-gray recessed sub-dials. It features a day-date window at 3 o'clock, a 30-minute counter at 12, a 12-hour counter at 6, and running seconds at 9. 

• Bezel: Bi-directional rotating slide rule used to convert units (e.g., feet to meters, miles to kilometers) and currencies.

• Crystal & Caseback: Scratch-resistant sapphire crystal with double anti-reflective coating; exhibition caseback revealing the signed Hamilton rotor. [

• Water Resistance: 100 meters (10 bar), aided by a knurled screw-down crown.