Marathon Steel Navigator w/ Date Automatic Unisex Watches 41mm Sapphire Nylon Defstan Strap Black. Packed with Swiss-precision and reliability the SSNAV-D Auto is developed for pilots and everyday adventurers. The watch represents the continued lineage of Marathons original Steel Navigator developed in partnership with the Kelly Air Force Base in 1986. Specifications for Marathon Steel Navigator w/ Date Automatic Unisex Watches: Manufacturer: Marathon Application: Watch Repair/Jewelry Sewing/Textile Gender: Unisex Dial Color: Black Band/Strap Color: Black Case Color: Steel Marker/Numeral Color: White Color: Black Case Finish: Parkerized Case Material: 316L Stainless Steel Case Diameter: 41 mm Bezel Finish: Parkerized Wrist Band Type: Strap Movement: Swiss Automatic Illumination Type: Tritium Water Resistant Mark: 10 atm Package Contents: Marathon Steel Navigator w/ Date Automatic Unisex Watches Ballistic Nylon Strap Marathon WW194030SS-0103: Steel Navigator w/ Date Automatic Unisex Watches 41mm Sapphire Nylon Defstan Strap Black