Ergonomic design wireless trackball mouse. Junk item. - Model: ERGO M575SPd - Brand: logicool - Type: Wireless - Features: Ergonomic design - Color: Black Thank you for viewing. Power turns on, but pairing mode is unstable. It always enters pairing mode when powered on, and the connection is unstable. Please note that warranty is not available with this product's serial number because I have used Logitech's warranty. Please consider only if you understand the above.