Logitech Mechanical Keyboard SIGNATURE K855 Logitech Model Number: K855 Color: Graphite Main Color: Black Bluetooth: Yes USB: Yes Key Switch: Mechanical Key Language: Japanese Tenkeyless: No Connection Method: BLUETOOTH+RADIO Compatible Battery Type: AAA batteries Purchased new and used for about a year. The response of about two specific keys is slow, so I'm selling it as junk. The condition is poor. Please understand that this is junk before purchasing. It will be sent with only the outer box and simple packaging.