Tactical, Professional, High Performance in 45 mm case size...The A-5S Ballista features professional tactical design in a durable 45 mm stainless steel case. All stainless steel components... case, crown, case back, band hardware... all are ION (or PVD) coated non reflective matte black. High performance components built into the A-5S Ballista include: A rugged screw down crown & case back, 200 M water resistance rating, scratch resistant hardened sapphire crystal, Swiss super luminous surrounds self powered continuous illuminating Swiss micro tubes in the hands & markers, lithium 10 year battery life powered precision Swiss made movement with a low battery alert, functional easy to read dial with 12 / 24 hour markings with date.