Features Since there is no human body standing wave, all kinds of vocal music are authentic, and the sound quality of each sound frequency band is very clear. Strong sound penetration, small size, easy to use. Size: 50*50*30mm Sound playback and sound expansion for computers, laptops, MP3, MP4, CDs, mobile phones and more. The speaker is full-frequency effect, and the bass is very strong, which is equivalent to the 8-inch bass effect of traditional speakers. The latest innovation, breaking through traditional limitations, 360° frequency transmission. Specifications: Color: steel Impedance power(Optional): 4 Ω 25 w;  8 Ω 20 w Type: electrodynamic (moving coil) Shape: round Diaphragm material: non-paper Magnetic circuit form: internal magnetic type Frequency characteristics: full spectrum band (full range) Rated power: 25W Frequency response: 20HZ -- 20KHZ (kHz) Directivity: positive Sensitivity: 95 (dB/W) Noise ratio: 90 (dB) Harmonic distortion: 5 (TMD %) Size: 50 * 50 * 30 mm/1.97*1.97*1.18inch Weight: 268 g Package Included: 1 x  Vibration Speaker Package List