Feature: 1. Bone Conduction: The speaker adopts bone conduction technology, through the resonance principle to produce a bass effect, large volume, providing a unique sound experience. 2. Dual Speaker Stereo: Support dual speaker connection to achieve stereo sound effect, bringing users a more three dimensional music experience. 3. Support Intercom: Bluetooth speaker built in microphone, support intercom function, convenient for users to make calls or voice talking. 4. FM Radio: This bluetooth bone conduction speaker has a built in FM radio function, you can listen to the radio program, rich music selection. 5. Multi Application: The bottom of the wireless speaker is equipped with suction cup, which can be adsorbed on flat surfaces, suitable for bathroom, car, outdoor and more. Specification: Item Type: BT Bone Conduction Speaker Material: Aluminum Alloy Speaker Diameter: Approx. 40mm / 1.6in Transmission: Wireless BT 5.3 Wireless Distance: Approx. 10m / 32.8ft Play Technology: Bone Conduction (Through the resonance principle of the speaker and the objects in contact, to achieve a small volume of large volume of bass effects); Dual Speaker Stereo (If you have two speakers, they can be paired together) Output Power: 3W Frequency: 20Hz-20KHz SNR: ≥85dB Impedance: 4 OHM(Ω) Microphone: Supported Battery Type: Built in 400mAh Li Battery. Package List: 1 x BT Bone Conduction Speaker1 x Data Cable 1 x Lanyard 1 x Double Sided Sticker 1 x User Manual Note: Manual measurement, please allow some errors.