The SEIKO Sportura Kinetic never needs a battery change - it charges with the movement of your body. This model features grey and blue on its stainless steel case, date display, rotating bezel, see-through caseback, and diver's water resistance (200M). All measurements are approximate and may vary slightly from the listed dimensions. Men's watch bands can be sized to fit 7.5-inch to 8.5-inch wrists. Click here to view our Watch Sizing Guide. Automatic movement winds with the movement of your arm. It is recommended that you wind the watch every two weeks. Screw-down crown: A screw-down crown (knob) creates a water-resistant seal. To unscrew the crown, turn counter-clockwise and pull/push into position to set time, date, and other functions. To close the crown, press it against the case and turn clockwise.