Benrus US Department of Defense issued the MIL-W-50717 Model: Type II Reference: Type II Class A Year: 1978 Case No: 1101 Material: Parkerized steel Dimensions: 42.5mm diameter; 15mm thickness Crystal: Plexiglass Lume: Yes, tritium Caliber: Self-winding Benrus caliber GS1D2 (Modified ETA 2620) Bracelet/Strap: HODINKEE Distress Beige Leather NATO Lug Width: 19.5mm Box/Papers: N/A Any questions, feel free to ask!