J306633 - Set of 6 Magna-Twist Magnetic Clasps/Extender by Garold Miller
Secure but large.
I bought these in the 2-tone choice. The magnets are certainly secure, sometimes a bit difficult to unscrew and then break the magnet's hold. My biggest problem with them is that they are quite large and heavy, plus add about an inch to bracelets, which make them just too long. I had to return them.
Makes life easier....
I LOVE these! So does my elderly mother. She has so many beautiful necklaces that she was unable to wear until I got these magnetic clasps for her. Just purchased 2 more sets ( 1 silver, 1 gold ) that I will share with her.
I have tried other magnets but have found this twist type to be more secure.