Features: 1. Turn any hollow core into a speaker: These bone conduction speakers are compact and versatile, allowing you to enjoy a unique sound experience in various environments. Use them with different hollow objects to create audio output. 2. Different sounds with different surfaces: Utilizing bone conduction technology, this speaker delivers a customizable audio experience. Placing it on various surfaces such as glass, wood, plastic containers, photo frames, or headphones can produce varied sound effects. 3. Portability: The device is small and lightweight, making it easy to carry and use on the go. 4. Small but powerful speakers: When used with suitable objects, the speaker can produce strong sound output up to 115 decibels, allowing for customized sound quality. It is recommended to use thin-walled objects like plastic containers or buckets for optimal performance. 5. Multifunctional speakers: Use the bone conduction speaker for listening to music, podcasts, making phone calls, participating in conference calls, playing games, or enhancing audio experiences. The speaker also supports FM radio functionality for listening to broadcasts. Specifications: Capacity: 400mAh Function: Bone Conduction Speaker, FM Radio Wireless Version: 5.0, A2DP, HFP Wireless Stereo Supported FM Radio Built-in Bone Conduction Transducer: 3Watt Frequency Range: 120Hz16kHz 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 differences in display screens may cause slight variations in the color of the item shown in images. Measurement error allowed is +/- 13 cm.