Stop guessing! Take the uncertainty out of seam allowances with our handy dandy seam gauge. Durable and beautiful laser cut iridescent acrylic. All markings are laser engraved so they'll never rub off! 1/8" thick acrylic. Features gauges for seam allowances of 1/4", 3/8", 1/2", and 5/8". Holes for your machine's needle for accurate allowance marking. 2" square with diagonal 45 degree markings