【Innovative Bone Conduction Technology】This sleep speaker uses bone conduction technology to deliver sound without disturbing others, perfect for a peaceful night's rest. 【Versatile Playback Options】Enjoy music via Bluetooth-compatible connection or TF card, supporting various audio formats including MP3, WMA, FLAC, APE, and WAV. 【Long-lasting Battery Life】With up to 15 hours of playtime at 80% volume, this device ensures uninterrupted sleep assistance throughout the night. 【Easy Operation】Features a multi-function composite key for simple control and LED indicators for clear status display. 【Comfortable Design】Simply place under your pillow for use, no need for in-ear wear, providing a comfortable and harm-free listening experience. Specifications: Horn type: 8Ω/2W Frequency response: 20HZ-20KHZ Bluetooth-compatible solution: BLUETRUM Bluetooth-compatible version: V5.2 Bluetooth-compatible protocol: A2DP 1.0 AVRCP 1.5 AVDTP 1.0 AVCTP 1.4 HFP 1.5 GAVDP 1.0 Decoding method: TF card (MP3, WMA, FLAC, APE, WAV); Bluetooth-compatible (SBC) TF card: Maximum support 32G (not included) Operation distance: ≥10 meters Normal working time: Play music: ≥15H (80% volume), standby time: about 15 days Prompt voice: English prompt tone LED light: Red and blue status indicator light Operation method: Multi-function composite key Battery capacity: 500mAh/3.7V Charging method: TYPE-C charging port Charging cable: 30cm TYPE-C charging cable Charging time: 2.0H Charging current: DC5V/310MA Charging voltage: 5V Product material: ABS+PC plastic shell