The Classic Curves Plus Ruler from Color Girl Quilts features:

-19 slots for cutting curved shapes for quilting
-slots range in size from radius of 4" - 13"
-lines on the ruler indicate placement of fabric for cutting concave and convex shapes (quarter circle, half circle, full set-in circle, orange peel).
-transparent non-slip surface on back of ruler
-instruction insert includes basic directions for use
-intended for use with typical rotary cutter