I am selling this item because I am replacing it. One of the non-slip pads on the bottom has come off. Also, the sticker on the bottom is peeling. The connection method is the type that uses a USB receiver. The receiver is stored on the bottom. There are no batteries for operation check. I was using it until just now, so I think it can still be used. If you want to try a trackball! Please consider it! Wireless mouse with trackball, easy-to-use design. - Brand: ELECOM - Model: EX-G M-XT3DR - Color: Black - Features: Trackball equipped - Design: Japanese design - Number of buttons: 5 buttons - Connection method: Wireless - Scroll wheel: Yes - Ball size: Large Thank you for viewing. Power source...Battery powered Other...Tilt wheel (horizontal scroll)