Features: 1. Turn any hollow surface into a speaker: This bone conduction speaker is compact and versatile, delivering a unique yet high-quality audio experience in various environments. 2. Sound variation with different surfaces: Utilizing bone conduction technology, this speaker transforms everyday objects into sound sources. Placing it on surfaces such as eyeglasses, guitars, cardboard boxes, plastic containers, photo frames, or dashboards produces distinct acoustic effects. 3. Portability: Lightweight and compact design for easy carrying and convenient use anywhere. 4. High-output performance: When paired with suitable resonant surfaces, the speaker delivers strong audio output, with sound pressure levels up to 115 dB. Thin, rigid materials—such as plastic buckets or similar hollow objects—are recommended for optimal performance. 5. Multi-functionality: Supports music playback, podcasts, hands-free phone calls, conference calls, gaming audio, and FM radio reception. Specifications: Battery capacity: 400 mAh Functions: Bone conduction speaker, FM radio Bluetooth version: 5.0, supporting A2DP and HFP profiles Stereo Bluetooth supported Built-in FM radio Bone conduction transducer power: 3 W Frequency response: 120 Hz – 16 kHz Built-in high-sensitivity microphone Battery type: 400 mAh polymer battery Charging port: USB-C (not compatible with fast charging) FM radio usage is recommended outdoors; connect USB cable during FM use. Material: Metal Color: Black Package includes: 1 x Bone Conduction Speaker 1 x Charging cable Note: Color appearance may vary slightly due to lighting conditions and display settings. Measurement tolerance: ±1–3 cm.