Sony FE 100-400mm f/4.5-5.6 GM OSS Lens - Manual (Page 59)

Put the left unit of the headset (the unit with the tactile dot) back into the left hole of the charging case, put the
right unit of the headset back into the right hole of the charging case, insert the units until they click, and then
make sure that the units are locked in the charging case.
Close the lid of the charging case.
By closing the lid once, the headset units are straightened and locked in place, even if they were not locked in
the charging case before.
2.
Hold the charging case in your hand and press the lid open button to open the lid. 3.
Press and hold the pairing button of the charging case for about 5 seconds. 4.
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