If you have a tattoo then you might have a problem with the new Apple Watch.
Some customers are complaining that a tattooed wrist can prevent the watch's heart rate sensor from working properly.
Apple says the watch uses infrared lights flashed at your skin to read heart rates.
Tattoo inks can block those lights.
You can turn off the wrist detection feature, but that shuts down other key functions or apps.
Apple has not commented on the customer complaints.