This unique tube clasp has a magnetic feature, with "jigsaw puzzle" type cut out sections that slide into place, keeping it quite secure. The inner diametre of this clasp is approximately 7mm (ie they will fit cord/ribbon/braid that is about 7mm wide), with a depth of approximately 5mm. The overall length of the two ends completed is approximately 22mm. Sold per pack of 1 set - you will receive what is pictured - two ends with a magnet attaching the two. To open this clasp, it is important not to try and "snap" the ends apart, but rather slide the ends away from each other. Hold the clasp so that the 'jigsaw' cut out faces the sky, and bring one side up to the sky, and one side down to the ground to open. Use a strong beading glue to glue in your cords to produce a beautiful finish on round leathers, knotting work (such as kumihimo), macrame and more.