Locking Magnetic Jewelry Clasps - Set Of 4, Goldtone - Jewelry Boxes. Locking Magnetic Jewelry Clasps - Set Of 4, Goldtone. Locking magnetic jewelry clasps make necklaces and bracelets simple to attach--locking safely in place. Just fasten magnetic jewelry clasps to jewelry for quick, easy on/off. Interlocking ridges keep magnets securely clasped. Lobster claws. Set of 4 locking clasps. 70% alloy/25% iron/5% magnet