1. Bone Conduction Speaker: Utilizing bone conduction technology, this sleep speaker transmits sound through the pillow to your auditory , ensuring eardrum friendly and listening experiences 2. Double Horn Sound: Featuring double horns, this pillow speaker offers 3D surround sound with clear and transparent high frequencies, rich and full low frequencies, catering to your pursuit of well sound quality 3. Playback Options: Easily connect the under pillow speaker via BT to your smartphone, tablet, and other devices, or use a small memory card (not included) for playback, allowing you to enjoy music anytime, anywhere 4. BT5.2 Connection: With BT5.2 chip, this speaker boasts lower power consumption, more stable transfer, quick connection to your phone for music playback, with higher processing performance, and clearer sound 5. Long Endurance: With a built in 500mAh high capacity battery, this bone conduction pillow speaker provides up to 20 hours of uninterrupted music playback, ensuring your listening experience remains continuous Item Type: Pillow Speaker BT Version: 5.2 BT Transfer Distance: . 10m / 32.8ft Protocols: A2DP, AVRCP, Charging Time: 2 hours Playing Time: 20 hours Small Memory Card Slot: Support up to 32GB Card (not included) Battery Type: 500mAH Polymer Li Battery (Built in) Color: As Shown Material: plastic Package Contents: 1 x Sleep Speaker 1 x Charging Cable 1 x Chinese and English instruction manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.