Inspired by the Model 23, a cutting-edge pocket watch used by U.S. soldiers during WWII, the Khaki Pilot Pioneer's distinctive design is a tribute to Hamilton's aviation and military heritage. The sporty yet refined pilot watch retains an indisputably technical feel with its handwinding mechanical movement, bi-directional rotating bezel and prominent winding crown. Available with a sleek stainless steel or unique bronze case, this 43mm timepiece is ready to fly.KHAKI AVIATIONThe Khaki Aviation collection perfectly displays Hamilton's technical know-how when it comes to creating reliable watches for pilots and urban aviators. MANUAL WINDINGWind your mechanical watch by turning the crown clockwise until it blocks.STAINLESS STEEL CASEA highly resistant alloy composed of steel and chromium. It can be worked to resemble a precious metal. It is nearly impervious to rust, tarnish, and corrosion.SAPPHIRE CRYSTALSynthetic sapphire crystal is a tough scratch-resistant material, only diamonds could leave a mark.WATER RESISTANCEYour timepiece is resistant up to 10 bar (100m) / 145 psi (328 ft).