It has microphone functions.(You can record your own voice through a microphone and through a speaker). Custom sound can be achieved through the included card reader (without a memory card, purchased by yourself) or your own USB drive. Universal for all kinds of 12V-24V cars and vehicles. Low energy consumption, and reliable performance, easy to operate. Input Voltage: 12V-24V DC Output Power: 25W Resistance:4Ω Easy to install anywhere with 12V-24V DC power Siren: 25 watt amplifier. Professional Installation Recommended: If you are installing this on your plug in your vehicle, you may need to increase the fuse on your outlet. Easy to install anywhere with 12V-24V Power. No installation guide provided, please consult with car audio installer or . Custom installation required. Requires 12V or 24V Power delivered to 2 wires. You may have to extend the wire between the speaker and the control module if you are mounting this in your engine bay. Note: Installation guide not included, Please check as much as possible to make sure the item is what you need. Tips: The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Colour:As Shown Material:Plastic Package Contents: 1 x Speaker Unit 1 x Amplifier 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.