[Easy to use] No tools are 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 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. [High quality material] The upgraded locking pin back is made of high-quality plated copper, which is and firm. The buckle design can firmly lock the needle to its safety without falling off or losing. [The ] 600 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., Manufacturer: Jnchdghwa