yueton Sewing Clips, Paper Clips, Blinder Clips, Multi-purpose Clips for Fabric Quilting Craft Sewing Knitting Crochet, 25 Pack Purple Material: High quality PVC and metal These clips feature great holding capacity and have a multitude of uses. Unique concave-convex design make a firmly grasp to any kinds of seam allowance. Open wide to hold layers of fabrics,Great alternative to pins. Useful in holding fabrics together for trimming, quilting, binding or sewing There are 5mm,7mm ,10mm,20mm,30mm mark lines on the side of the clip. Help to do more precise sewing.