The CornerDuo Sander by Wallboard Tools is a lightweight, dual-purpose sanding tool designed for internal plasterboard corners. It features both a pole sander head for floor-to-ceiling reach and a hand-held head for detailed finishing. The tool adjusts between 80° and 90° to match various internal corner profiles, making it ideal for sanding tight or triple corners. Compatible with CornerDuo sanding pads (CD-220-5), it offers minimal drag and smooth operation for professional drywall and plastering applications.