This 3 pack of rulers have a 1" wide ruler on one side and seam allowance guide for either 1/4" or 1/8" on the other side making the ruler 2" wide. 3 lengths included are 6", 9" and 12 1/2". Made from Yellow Fluorescent Acrylic so edges appear to light up using light from the room instead of casting a shadow on the edge as some clear acrylic rulers sometimes do.