Amazon.com: Microsoft Wireless Mobile Mouse 4000 - Graphite. Comfortable Ergonomic design, Wireless, USB 2.0 with Nano transceiver for PC/Laptop/Desktop, works with Mac/Windows Computers : Electronics
Microsoft Wireless Notebook Optical Mouse 4000 Model 1050 /w USB Receiver | eBay
Microsoft Wireless Notebook Optical Mouse 4000, P/N: B2P-00006