One part stainless steel, two parts testosterone, the Seiko Sportura is a marvel of time-keeping engineering. The Sportura Kinetic Chronograph features an automatic power generator that operates by the natural movement of your wrist, making it independent of conventional storage batteries. The Seiko Sportura's chronograph stopwatch function measures up to 45 minutes in 1/5 second increments, and features both an overcharge prevention function and an energy depletion forewarning function. The duration of a full charge is approximately five months. With its screwdown crown and screwdown see-through caseback, you can rest assured that the Sportura is built to Seiko's extremely tough standards for material quality and durability. Protected by scratch-resistant sapphire crystal, the Seiko Sportura is water resistant to 100m.