Note: MK220, MK240, MK260, MK270 keyboard and mouse sets are available in both new and old versions. The receiver is different. This receiver is compatible only with the new version, which has a serial number starting with SN14, SN15, or SN16. Feature: This original Nano receiver can connect both keyboard and mouse simultaneously. There is no functional difference between the original and this receiver, and drivers recognize it normally. Compatible with MK220, MK235, MK240, MK260, MK270, MK275, MK345 wireless keyboard and mouse sets, and supports mouse models such as M150, M210, M212, M185, M170, M238, M220, and other compatible single mice. How to use the USB receiver: When you receive the new receiver, you must pair it with your mouse. Note: The product comes with the manufacturer's logo. Thank you for your understanding. Package list: 1 x USB Receiver