From the manufacturer:
The Omnigrid ruler grip is a hand-held accessory that features double suction cups for attaching to rulers or templates. It provides a steady grip on your ruler and keeps your fingers away from the rotary cutting blade while you're cutting fabrics for quilting, sewing and crafting projects. The ruler grip makes for a perfect addition to your crafting or sewing kit.
- 2 Large suction cups with handy lock and release levers
- Easily and quickly move ruler and hold in the exact position needed
- Protects hands and fingers from cuts and has a comfortable grip handle
- Attaches best on rulers or templates at least 2.25 inches in diameter