Description:Easy to attach: these pin backs with 2 or 3 holes, and their backs are flat, so you can stick the attached crafts with glue, or sew the hole directly.Secure safety pin backs: with annular bayonet design, not easy to drop and fall apart; Stainless steel plated, not easy to get rusty.DIY crafts accessory: brooch backs are good for attaching beads, dangles and various jewellery findings to create an unique and personalized ornaments.More uses: pin backs can be glued onto most surfaces to DIY crafts, suitable for jewel crafting, sewing fabric, making corsage, name badges and more.Material: IronSpecification:21.5x5x0.6mm/0.85x0.20x0.02inch, 30 Pieces26x4.5x0.5mm/1.02x0.18x0.02inch, 30 Pieces33x4.5x0.5mm/1.30x0.18x0.02inch, 20 Pieces39.5x4.5x0.5mm/1.56x0.18x0.02inch, 20 PiecesHole 2mm/0.08 inchPackage Includes:100 Pieces Back Safety Pin CraftNote:Since the size above is measured by hand, the size of the actual item you received could be slightly different from the size above.Item color displayed in photos may be showing slightly different on your computer monitor since monitors are not calibrated same.