Features: 1. Turn any hollow core into a speaker: These bone conduction speakers are compact and versatile, enabling a unique sound experience in various environments. Use them to transform everyday objects into functional speakers. 2. Different sounds with different surfaces: Utilizing bone conduction technology, this speaker delivers a customizable o experience. Experiment with various surfaces such as glasses, guitars, paper boxes, plastic containers, photo frames, headphones, or dashboards to achieve diverse sound effects. 3. Portability: Designed with a compact size and lightweight build, this speaker is easy to carry and use on the go. 4. Small but powerful: When attached to suitable objects, the speaker can produce strong sound output up to 115 decibels, allowing for personalized sound quality. Thin materials like plastic containers or buckets are recommended for optimal performance. 5. Multifunctional use: Enjoy music, podcasts, phone calls, conference calls, gaming, and immersive o experiences. The built-in FM radio function allows for additional entertainment options. Specifications: Capacity: 400mAh Function: Bone Conduction Speaker, FM Radio Wireless Version: 5.0, A2DP, HFP Supports Wireless Stereo Built-in FM Radio Bone Conduction Transducer: 3Watt Frequency Range: 120Hz - 16kHz Built-in High-Sensitivity Microphone Battery: 400mAh Polymer Battery Charging Port: USB-C (not compatible with fast charging) Recommended to use FM function outdoors; connect USB cable during use. Material: Metal Color: Silver Package Contents: 1 x Bone Conduction Speaker 1 x Charging Cable Note: Light reflection and display differences may cause slight variations between the product color in images and the actual item. Measurement error tolerance is +/- 1-3cm.