Corner Rounder Size 4mm, 7mm and 10mm. Material: Plastic, Approximate Size LxBxH: 6x7x3.5 cm. 2. It is a smooth, curved corner and a reverse-curve notch. 3. It is Ideal for rounding corners on photos. 4. It is to easy clean up they come equipped with a holder to catch the cut off pieces.5. You can round corners easier and more quickly using the angle eater.