Features: 1. Turn any hollow surface into a speaker: These bone conduction speakers are compact and versatile, delivering an immersive sound experience in various environments. Use them on different surfaces to enjoy unique audio playback. 2. Unique sound experiences on different materials: Utilizing bone conduction technology, this speaker allows you to explore varied acoustic effects. Place it on surfaces such as glass, wood, plastic containers, photo frames, or headphones to experience distinct sound characteristics. 3. Portable design: Lightweight and compact, this speaker is easy to carry for use at home, outdoors, or on the go. 4. Powerful audio output: When used with suitable surfaces, the speaker delivers strong sound performance up to 115 decibels, with customizable audio quality. Thin and rigid materials like plastic containers or buckets are recommended for optimal results. 5. Multi-functional use: Enjoy music, podcasts, phone calls, conference calls, gaming, or movie audio. The built-in FM radio function allows for additional entertainment options. Specifications: Capacity: 400mAh Functions: Bone Conduction Speaker, FM Radio Wireless Version: 5.0, A2DP, HFP Supports Wireless Stereo Audio Built-in FM Radio Bone Conduction Transducer: 3W Frequency Range: 120Hz - 16kHz Built-in High-Sensitivity Microphone Battery: 400mAh Polymer Battery Charging Port: USB-C (no fast charging support) Recommended to use FM function outdoors; connect USB cable during outdoor use. Material: Metal