This authentic Cartier Santos 100 dark brown (almost black) alligator leather watch strap was removed from a Santos watch model number 2878. It your watch has the code 2878 on the back of it then this strap will fit your watch.

Your watch strap is 20mm wide where it connects to your watch and is 18mm wide where it connects to your buckle. Each strap piece is 10.5cm long.

I have given you photos of your watch strap from every angle. Please use them to add to this description.

If you are not sure if this will fit your watch or if you have any other questions then message me. I'm here to help you.