Bluemoona 20 Sets - 13mm 1/2" Hidden Invisible Sew-In Magnetic Snap PVC Closure Purse Fastener Snap diameter: 13mm or 1/2" Square pvc size:28mm or 1.1" snap is covered with a PVC for sewing your snap into your application Magnetic button for easy opening and closing Easy to sew over with machine, making it completely invisible on the outside of the bag Use on bags, totes, backpacks, jacket pockets, purses and lanyards.