This Memorex RF optical ScrollPro mouse combines today’s latest technology into one convenient mouse! Radio Frequency (RF) means cordless operation anywhere….no direct line of sight is need the mouse and the receiver. Optical technology ensures precise cursor control and no mouse ball to clean! This Memorex mouse’s 5-buttons (3 of them are programmable) allows users to easily navigate documents as well as the Internet. The fifth button is also the scroll wheel which makes web surfing a snap. The optical design feature makes mousepads and “dust bunnies” a thing of the past, and with no mouse ball allows this mouse to operate on any flat surface. This Memorex RF optical mouse is even rechargeable using the included mouse port charging station and rechargeable batteries!!