IF YOU WANT BUTTONS FOR SEWING WITH LOOP - DO NOT ORDER FLAT BACKS WHICH DO NOT HAVE THE LOOP. Cover buttons are great for sewing and crafting projects. Available in sizes 20(1/2), 24(5/8),30(3/4),36(7/8),45(1 1/8),60(1 1/2) and 75(1 7/8). Wire eyed backs work great for sewing projects, hair ties, bows and other items that need to be secured with thread or tided down. The flat backs are fantastic for glueing crafts, smaller sizes for earrings, shoe clips, larger sizes for Stethoscope IDs, magnets, barrettes, bookmarks... you get the idea if you need your own fabric to cover a button this is the product for you.