Rectangle Alloy Magnetic Clasps with Glue-in Ends for Jewelry Making, PlatinumSize: about 18mm long, 15mm wide, 11.5mm thick, half hole: 10x7mm.Excellent for bracelets or necklaces making. They have great strong magnets which can help to connect your favourite necklaces or bracelets. This is a very easy design and must bring your jewelry more personal feeling.