What is a MAC?

Every wireless device has a MAC address. It is a unique code set at the factory. You can think of it as the device’s serial number for wireless communication.

A MAC address is 12 characters long. It is usually written in pairs separated by colons, for example:

34:85:18:A1:2B:3C

It only ever contains the numbers 0 to 9 and the letters A to F.

Why does HandShake need it?

The watch and the receiver each need to know the other’s MAC address: