Features: 1. Turn any hollow core into a speaker: These bone conduction speakers are compact and versatile, enabling a unique audio experience in various environments. Transform everyday objects into sound sources with ease. 2. Different sounds with different surfaces: Utilizing bone conduction technology, this speaker delivers a customizable audio experience. Experiment by attaching it to various surfaces such as glass, wood, plastic containers, photo frames, or headphones to enjoy a range of acoustic effects. 3. Portability: Lightweight and compact design makes it easy to carry and use anywhere. 4. Small but powerful speakers: When placed on suitable resonant surfaces like thin plastic containers or buckets, the speaker can produce strong sound output up to 115 decibels, allowing for personalized sound quality. 5. Multifunctional speakers: Ideal for listening to music, podcasts, making hands-free calls, participating in conference calls, or enhancing gaming audio. The built-in FM radio function allows you to tune into radio stations and enjoy audio content on the go. Specifications: Capacity: 400mAh Function: Bone Conduction Speaker, FM Radio Wireless Version: 5.0, A2DP, HFP Supports Wireless Stereo Audio 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 for optimal performance Material: Metal Color: Silver Package Contents: 1 x Bone Conduction Speaker 1 x Charging Cable Note: Lighting effects and display settings may cause slight color variations between the image and the actual product. Measurement tolerance: +/- 1-3 cm.