Clasps converters are usually made up of a magnetic clasp linked to a clasp with a secure hooking mechanism (spring ring, trigger, etc.). These types of clasps can be added to a regular necklace and easily convert it into a necklace with a magnetic clasp with no prior jewelry-making skills.
It also makes your necklace design easy to put on or take off. Simply use the spring ring or trigger clasp to hook one end of the magnetic clasp to the open end of the design (the side not featuring the clasp). Then, hook the other end of the magnetic clasp to the clasp already attached to your jewelry design. You can easily convert back to the original design this way, too.