Reddit reviews Mudder Locking Pin Keepers Backs, No Tool Required (Silver, 30 Pieces)

Package contents: each pin sizes is approx. 10 mm/ 0.4 inch in diameter, comes with small clear box packed to avoid locking pin backs losingMaterial: pin backs is made of quality nickel plated brass, sturdy and small; Small size makes it unobtrusive while maintaining stability; The metal material makes it durable and colorfast, giving you an incredibly sturdy and safe experienceFeaturing a spring-loaded fastener: these pin backings are easy to put on and take off without a tool; Simply push to secure onto pin post while holding onto your pin to release; These locking pin backs are very smooth and prevent the skin from getting stuck injuryDelicate design: the pin backs match for most metal pin; Metal pin backs provides good grip of pin to keep it stay in place; Its firm and protective grip assures that you will never lose another pinWide usage: the metal pin back can be applied when tie tacks and lapel pins lose their back, or for homemade craft pins, suitable for brooches, name tags, display books, hanging ropes, bags, vests, hats, badges, collections, etc.