Ref. : FBLS.02.BC.01 / FBLS.02.BC.02S / FBLS.02.BC.03 / FBLS.02.BC.04S / FBLS.02.BC.05SClasp FBLS.01.BH.01 is the ancestor of the current box clasp. FBLS.01.BH.02 is the same secure model on the side. The luxury model FBLS.01.BH.03 is used by major jewelery houses up to 19 centuries. The safety at the top of the blade FBLS.01.BH.04 is very characteristic. These clasps are used in case of need of clasp with a minimum thickness. They can be integrated under a cameo or under a stone and become virtually invisible.