Sennheiser VMX100-B Instruction Manual page 12

Then switch on the headset (details on page 10) and pair it to
your mobile phone. For details and information on how to pair to
another Bluetooth device see page 12.
ON
Put the headset on your ear.
(un)muting (p. 16)
ending calls (p.14)
redialling (p. 14)
8
VMX 100
OK
Keyword
0000
accepting calls (p. 13)
voice dialling (p.14)
volume (p. 15)