Fairbairn–Sykes fighting knife

The Fairbairn–Sykes fighting knife is a double-edged fighting knife resembling a dagger or poignard with a brass or wooden foil grip. It was developed by William Ewart Fairbairn and Eric Anthony Sykes in Shanghai based on ideas that the two men had while serving on the Shanghai Municipal Police in China before World War II. The F-S fighting knife was made famous during World War II when issued to British Commandos, the Airborne Forces, the Special Air Service (SAS) and many other units, especially for the Normandy landings in June 1944.

Source: Wikipedia — Fairbairn–Sykes fighting knife (CC BY-SA 4.0)