Environmentally friendly Pulsar 4000 Solar technology charges from any light source as you wear it. Stores energy and runs uninterrupted for up to 180 days when fully charged - with quartz accuracy and no batteries to change! Date One-way rotating elapsed time bezel lets you time dives or other events. Step-motion second hand will move in 2-second intervals when power is reach a level of less than 72 hours and needs to be exposed to light for charging Quick-start function - exposure to light for 2-3 seconds will activate the watch movement Overcharging prevention function Stainless steel case with hard rubber accents Pressure vented rubber strap Luminous hands and markers for low light visibility Screwdown crown and caseback Water-resistant to 200 meters Approx. width 1 3/4 inches (mm) not including setting crown.