[High quality material] The upgraded locking pin back is made of high-quality nickel plated copper, which is and firm. The buckle design can firmly lock the needle to its safety without falling off or losing. [Easy to use] No tools are needed. The spring pin design is easy to lock and remove. Just push the base to lock and fix it, and pull to release the lock and remove it. Replace the latch at any time. [Widely used] The metal needle back is suitable for needles, lapel needles, name tags, display books, lanyards, bags, vests, hats, cowboy buttons, badges, enamel needles, DIY crafts, etc. [The ] 300 PCS needle back lock with clear storage box makes storage more convenient. The size of the needle back is 0.4 inch diameter and 0.25 inch height. It is small and easy to use. Better meet your and your family's decorative needs. Material: Metal colour: Silver Package Contents: 300 x pin clasps back locking Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.