M2616 Handsfree Set

Key 1 is the bottom key on the right column.
Keys 2 to 7 starts from the key above key 1 counting up.

Key 8 is the bottom key on the left column.
Keys 9 to 14 starts from the key above key 8 counting up.

Program is the topmost key on the right column.
Handsfree/Mute is the topmost key on the left column.

M2008 and M2008HF

Key 1 is the bottom key.
Keys 2 to 8 starts from the key above key 1 counting up.

M2006

Key 1 is the bottom key.
Keys 2 to 6 starts from the key above key 1 counting up.