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. Transform everyday objects into audio sources with ease. 2. Different sounds with different surfaces: Utilizing bone conduction technology, this speaker delivers a customizable audio experience. Sound quality varies when attached to different materials such as glass, wood, plastic containers, photo frames, or headphones, offering a range of acoustic effects. 3. Portability: Lightweight and compact design makes it convenient for travel and everyday use. 4. Small but powerful: When paired with suitable resonant surfaces like thin plastic or hollow objects, the speaker can produce strong sound output up to 115 decibels, allowing for personalized sound quality. 5. Multifunctional use: Enjoy music, podcasts, phone calls, conference calls, gaming audio, and immersive sound effects. Built-in FM radio functionality allows for direct radio reception. 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 with USB cable connected. Material: Metal Color: Silver Package Contents: 1 x Bone Conduction Speaker 1 x Charging Cable Note: Light reflection and display settings may cause slight color variations between the image and the actual item. Measurement tolerance: +/- 1-3cm.