The Citizen Promaster Tough timepiece features a monocoque case (2 piece construction resulting in no caseback) resulting in extreme rigidity, shock resistance and anti-magnetism. Super Titanium™ coating on a SS case and bracelet allowing for anti-rust, scratch resistance, hypo-allergenic and 5X harder than SS. Also features ISO compliancy, anti-reflective sapphire crystal, super LumiNova hands and markers and ability to function in extreme temps. Features our Eco-Drive tech–powered by any light