Features: 1. Turn any hollow core into a speaker: These bone conduction speakers are the smallest and most versatile bone conduction speakers available, allowing you to enjoy a unique sound experience in any environment. Transform any hollow surface into a speaker anytime, anywhere. 2. Different sounds with different surfaces: This speaker uses bone conduction technology to deliver a customizable audio experience. You can test and enjoy varied sound outputs—similar to using different instruments. Placing it on surfaces such as glasses, guitars, paper boxes, plastic containers, photo frames, headphones, or dashboards creates diverse sound effects. 3. Portability: This product is compact and lightweight, making it easy to carry. 4. Small but powerful speakers: When paired with the right object, these bone conduction speakers can produce strong audio output, reaching up to 115 decibels, allowing for customized sound quality. It is recommended to use thin materials such as plastic boxes or buckets for optimal performance. 5. Multifunctional speakers: Use the bone conduction speaker for listening to music, podcasts, making hands-free phone calls or conference calls, playing games, and enjoying immersive game audio. The speaker also functions as an FM radio, enabling music playback and podcast streaming. 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; 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 color variations between the image and the actual item. Measurement error allowance: +/- 1–3 cm.