The S300 series is a classic watch with a high-beat 4Hz movement. It means that the second hand of the watch tics 8 times within a second instead of the normal one tic per second. On top of the hi-beat movement, the watch comes equipped with 5 ATM water resistance and Hardlex mineral glass. The simplicity of the dial and design makes the SL300 an extremely versatile all-around watch. If you are looking for a simple watch with a clear representation of time that doesn't require a battery to work, the Airmaster S300 series is definitely for you.
The Automatic Airmaster SL300 is an automatic self-wind mechanical watch, which means that it doesn't require a battery. Hand-wound watches need to be winded before use. After the first winding, the watch will keep moving and winds itself automatically from natural hand movement if used at least 8 hours during the day.
Stop winding the watch when you feel the resistance. If you overwind the watch, the spring might break.