Rotary trimmer features a concealed rotary blade that glides smoothly up and down the trimmer for precise cuts. Versatile design allows you to switch out the blade type for different cut edges. Straight blade provides a standard straight edge. The wavy blade creates a scalloped edge for crafts. Perforated blade makes pre-cut marks for easy detachment. Each blade has a 12" cutting length and can cut up to 15 sheets at once. Plus the square cutting mat can be rotated up to four times to maximize the number of accurate cuts before replacing.