Kecheer 8pcs Dry Erase Markers with Eraser Cap Whiteboard Pen Set for Glass/ Whiteboard/Plastics/Porcelain - Walmart.com
The New Glass Captcha – ideal for any boardroom or office | Glasswipeboard's Blog
Kassa Clear Dry Erase Board Sticker - 18" x 78” (6.5 Feet) - 3 Dry-Erase Board Markers Included - Transparent White Board Film for Refrigerator, Desk, Office - Glass Whiteboard for Wall Alternative - Walmart.com
Using a window as a dry-erase surface - Home Improvement Stack Exchange