... calculator.Memory Calculation: M=, M-, MRC 2. 3 Port USB Hubs. 3.mood light with Mousepad Calculator Mouse pad ... with 3 Port USB Hub Functions4 USB 1.1 hubs (one in ... normal. Otherwise, please install the battery again. Adapter usageInsert an adapter into the socket for power, then the blue ... 180*14MMDetail picture: Calculator Mouse pad with 3 Port USB Hub