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 headphones, offering diverse 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 like thin plastic containers or buckets, the speaker can produce strong sound output up to 115 decibels, with adjustable sound quality. 5. Multifunctional speakers: Supports music playback, podcasts, hands-free phone calls, conference calls, gaming, and movie audio. Built-in FM radio allows for direct radio reception. 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 (does not support fast charging) Recommended to use FM function outdoors; connect USB cable for optimal performance Material: Metal