The size of a Tox address in bytes. Tox addresses are in the format [Public Key ( PUBLIC_KEY_SIZE bytes)][nospam (4 bytes)][checksum (2 bytes)].
The checksum is computed over the Public Key and the nospam value. The first byte is an XOR of all the even bytes (0, 2, 4, ...), the second byte is an XOR of all the odd bytes (1, 3, 5, ...) of the Public Key and nospam.