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. Use them to transform everyday objects into functional speakers. 2. Different sounds with different surfaces: Utilizing bone conduction technology, this speaker delivers a customizable audio experience. Sound varies when attached to different materials such as glass, wood, plastic containers, photo frames, or metal surfaces, offering 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 paired with suitable resonant surfaces, these speakers can produce strong sound output up to 115 decibels, with adjustable sound quality. Thin, rigid materials like plastic containers or buckets are recommended for optimal performance. 5. Multifunctional speakers: Supports music playback, podcasts, hands-free phone calls, conference calls, and gaming audio. Includes built-in FM radio functionality for listening to radio stations and audio content. 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 stable performance Material: Metal Color: Silver Package Contents: 1 x Bone Conduction Speaker 1 x Charging Cable Note: Light reflection and differences in display settings may cause slight variations between the product color in images and the actual item. Measurement may vary by +/- 1-3cm.