All kinds of mouse can be smoothly used on the slippery surface of mouse pad. Extend USB port can connect to any USB peripherals. USB 1.1 (2.0) version, tansfer rate: 12Mps (480Mps). SD/MMC card reader: USB 2.0 version; transfer rate: 480mps; read and write SD/MMC/MMCⅡ/Mini-SD/RS-MMc/Micro-SD. Mini speaker: audio output: 2.0 doube channels; output resistance: 2W/4 Ohms × 2; output power: 4W. Ferquency response: 200Hz-20kHz. Inside microphone. Flashing light around the pad when it works. Allows matching outside power of DC 5V.