Using your LEFF Amsterdam T40 Tube Watch is a breeze. Just put on the strap like you would with any other watch. Thanks to the quick - release system, if you want to change the strap, simply push the small buttons on the sides of the strap near the watch case, and the strap will come off easily. Then, attach your new strap in the same way.
When it comes to water resistance, this watch can handle splashes and short periods in the water (up to 3 ATM), but it's not suitable for swimming or diving. Avoid exposing it to high - pressure water.
To keep your watch in great condition, clean the case and strap regularly. Use a soft, dry cloth to wipe off dirt and fingerprints. For the leather strap, avoid getting it wet for long periods as it may damage the leather. If you use the Nato strap, it's more water - resistant, but still, try to dry it properly after it gets wet. Also, store your watch in a cool, dry place when you're not wearing it. This will help preserve its quality and keep it looking great for a long time.