1. and high-quality products. 2. Made of high-quality materials, durable and practical. 3. Fine workmanship and good performance. 4. Long service life. 5. A special amplifier board for electret microphones powered by 48V phantom power, universal and single-point electret microphones. By matching the microphone with different parameters, it can be used for karaoke, recording, conference speech and so on. The bottom noise of the amplifier board has a lot to do with the microphone. It is recommended to use a low-noise electret microphone to achieve the desired effect. Type of microphone used:electret microphone Frequency response and sensitivity:(depending on the use of microphone) Output impedance:250 ohms Sound pressure level:125db Signal to noise ratio:60db Power supply:15-48v phantom power Working current:about 3.2ma Board size:45mmx15.82mm (cannon head part is not included) Colour:Black Material:PC+Metal Package Contents: 1 * Microphone amplifier board Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm. Product Notes: Please allow a little manual errors.Due to the lighting of the photos and the difference of monitors, the pictures may not reflect the actual color of the real item. Please confirm acceptance before ordering. About Shipping: Please ensure your shipping informations are correct to avoid delivery issues. All orders are shipped within 3 days after payment. Delivery usually takes 8–12 days, The specific delivery time is depend on circumstances. If you have any questions during your purchase, feel free to contact us. We will respond you within 24 hours.