Using your TAG Heuer Aquaracer Professional 300 is easy. Just wind the crown gently to set the time and date. You can wear it for swimming or diving as it's water-resistant up to 300 m, but don't press the buttons underwater. When it comes to maintenance, keep it clean with a soft cloth. Have it serviced by a professional every few years to ensure it runs smoothly. Avoid exposing it to extreme temperatures or magnetic fields, as these can affect its performance.