about this projectMaterialMade of PVC rubber material, soft and lightweight, strong and durable. The rubber back provides good pin grip.Needle Back Size11.5mm/0.45 inches in diameter. 8mm/0.31in high. Quantity: 50pcs Rubber Pin Backing. Colour: Black.Easy to ApplyThese pin backings are easy to install and remove. The needle back is tight enough to not fall off easily.Rubber Pin RetainerGreat choice for replacing butterfly and rubber clutches.WIDE APPLICATIONPerfect for lapel pins, tie tacks, service bars, badges, name tags, DIY jewelry making and more. Can be placed on purses, bags, jackets, shirts and more.