Audio-Technica ATH-ANC300TW QuietPoint Noise-Canceling True Wireless In-Ear Headphones - Manual (Page 6)

5
The effective communication range of this product varies
depending on obstructions and radio wave conditions.
For a more enjoyable experience, please use the product as close
as possible to the Bluetooth device. To minimize noise and sound
disruptions, avoid placing your body or other obstacles between
the product’s antenna and the Bluetooth device.
For a more comfortable Bluetooth® communication experience
Antenna