Sennheiser MOMENTUM True Wireless 3 Noise-Canceling In-Ear Headphones (Graphite) - Manual (Page 22)

Using the earbuds
22 | MOMENTUM True Wireless 3
Pairing a spare earbud
The right and the left earbud are paired with each other upon deliv-
ery. If, however, you are using a different earbud (e.g. a spare ear-
bud), you have to pair the two earbuds with each other once. This
pairing process resets the earbuds to the factory default settings.
1. Insert both earbuds into the charging case and leave the lid of the
charging case open.
2. After 20 seconds, the earbuds are paired with each other.
The LED of the charging case then lights up red and green 3x.
The earbuds are now paired with each other.
If you have closed the lid of the charging case too early, repeat
the above procedure.
After the pairing process with a spare earbud, all settings are
reset. Pair the earbuds with your smartphone again (> 20).
1 2
20s
Connected
3 x
Keep open
L
R