The Mark XI, introduced in 1948 by International Watch Company (IWC) and Jaeger-LeCoultre (JLC), adhered to British Ministry of Defense (MoD) specifications, emphasizing functionality. Both models shared similar size and style due to these standards. JLC ceased production around 1953, while IWC continued until the early 1980s. Notable features include:

- Broad Arrow Markings: Indicating government property on the dial, movement, and case.
- Caseback Engraving: "6B 346 646/51" denotes the model and its 1951 production order.
- Caliber 89 Movement: A reliable, manually wound movement essential for British pilots' accuracy.
- Military Watch Features: Fixed spring bars, luminous dial and hands, hacking seconds, and a soft iron cover for anti-magnetism.

This example, with a flat hour hand, was issued to the Royal Air Force (RAF) and is coming with Certificate of Authenticity issued in 1999.

Case: Very nice Vintage condition case that has been polished in the past and is showing some wear from age. Engravings on the case are crisp and intact, show a delivery year for the watch in 1952
Dial: Excellent black matte dial showing Tritium markers at 3,6,9 and 12. The dial is correctly marked T at 6 o clock
Size: 36mm
Movement: Manual, Cal.89
Strap: Generic leather strap with IWC pin buckle
Inventory number: 3.2.365
Serial number: 1266XXX/2xxx

---

---