From the manufacturer:
This fantastic acrylic ruler is just for paper crafts! Featuring a beveled edge on one side for measuring and marking with a metal strip down the other side for use with straight blade and rotary cutters. This clear acrylic ruler features twelve inch ruling down to the 1/16 of an inch on the beveled side and a centering ruling grid down to the 1/4 of an inch on the other side. Ruler measures 12-1/4x2in.