Excellent measuring tool to set an accurate and consistent seam allowance. 10" Ideal Seam Guide - Amazing straight edge tool w/ Sew Tacky TechnologyTM in aiding sewers to sew straight seams, and a 10" curved Ideal seam guide with notch - use curved edge for curved seams and use the notch to wrap around your walking foot. The guide is made with Sew Tacky TechnologyTM, a military grade rubber and are thick enough to provide a fence for your fabric as you guide it to the needle. You can re-position the Ideal Seam Guide hundreds of times! When the Ideal Seam Guide loses its grip, gently wash it with a multi-surface cleaner, rinse it and let it air dry. The Ideal Seam guide regains its grip again and again!