Marathon Steel Navigator Black Nylon Ballistic Strap 12in Black 41mm. 412 HeavyDrive-PreciDrive Quartz movement the 41mm Steel Navigator (SSNAV) stands out with unmatched precision featuring accuracy of 10s/year. The SSNAV is built from 316L surgical-grade stainless steel with a screw-down crown and synthetic sapphire crystal making it operational even when submerged to 10ATM (100m/300ft). The refreshed case design features enhanced lug tapering providing a comfortable fit making the SSNAV ideal for all-day wear. The increased height of the 12HR GMT bezel is specially designed to provide improved grip allowing pilots to easily handle the bi-directional rotation while wearing flight gloves. The bezel also features inset-painted indices enhancing the legibility of the markings. Self-contained tritium gas tubes on the hour markers and minute/hour hands ensuring constant visibility in low-light environments. Tritium tubes are self-illuminating containing an isotope of hydrogen that won't dull down over time like photoluminescent paint meaning the watch will remain fully legible at all hours. Protecting the dial of the SSNAV is a highly durable sapphire crystal. This allows the watch to withstand extreme changes in air pressure - necessary for the watch's use by military pilots at altitudes of over 35000ft - while also providing scratch resistance and pristine clarity. The SSNAV is Swiss-made and Canadian-designed for premium quality and craftsmanship. Specifications for Marathon SSNAV 41mm Steel Navigator Watch: Manufacturer: Marathon Application: All Round Gender: Unisex Dial Color: Black Band/Strap Color: Black Case Color: White Case Material: 316L Surgical-Quality Stainless Steel Case Diameter: 41 mm Wrist Band Type: Strap Movement: Quartz Illumination Type: Tritium Package Contents: Marathon SSNAV 41mm Steel Navigator Watch Marathon WW194001SS-0803: Steel Navigator Black Nylon Ballistic Strap 12in Black 41mm