Logitech MX ERGO All functions are currently usable, but as shown in the attached images, the rubber on the exterior has undergone hydrolysis? Also, the battery drains quickly. Replacing the battery didn't fix this. This unit has been disassembled before. The battery drain issue hasn't improved, so there's a possibility of a malfunction. The battery is a replacement. Operation from this point forward is not guaranteed. Please make your judgment after confirming everything in the attachments. No warranty is provided for odors, stains, scratches, or operational status. Please feel free to ask if you have any questions. The contents are limited to what is attached. Shipping will be in the attached package + air packaging only. Ergonomic design trackball body, with signs of use. - Model: Trackball body - Accessories: Ball, USB receiver, cover - Color: Black - Features: Ergonomic design - Condition: Used Thank you for viewing.