An approx 10x13mm magnetic clasp, made of an alloy of metal that is nickel free and antique silver plated. In addition to the internal magnet, each half has a small prong that inserts into a hole in the other half, making it very difficult for the magnet to open otherwise than lifting the 2 halves apart. So no unexpected openings! End holes size is approx 1.2mm.
Price is for 1 magnetic clasp set of 2 halves.