Unlike other memory mouses that depend on a receiver that hogs the USB port. With the memory mouse 8000 relies on one of those factors, the receiver includes 1GB of flash memoryserving as a double duty.But once you remove it to copy files to or from another system, the mouse stops working. Another thing is that the mouse isn’t powered on batteries but a built-in rechargeable battery that can be recharged VIA USB and includes a special cable with magnetic connectors that attach to the receiver and under the mouse allowing it to recharge whenever needed. This still might not beat the Logitech, but it’s pretty good on average. $100