THESE ARE VERY SMALL!!! 4.5mm spring rings are about as small as any jewelry comes with.LISTED with 6mm Spring Ring item 154451170145 RHODIUM PLATED That is a very thin layer of the most valuable precious metal over solid 14k gold. This has a brilliant shine like chrome or freshly polished sterling, vs a yellowish white gold. Almost every high end or designer white gold item is rhodium plated. This clasp is: 4.5mm diameter X 15mm including 4.5mm Spring Ring clasp 3/16" X 5/8" this will add a 1/2" to items a dime coin is 17.5mm In our opinion, suitable for chains up to 25grams. You be the judge for yourself. No hassle returns. It is strong enough to hold one side & slide all around the Nickel without it even starting to come apart. Spring ring and other clasps WILL be slightly attracted to the magnet, as their internal springs are steel. Rest assured these are solid 14k NOT responsible for any damage or losses due to clasp failure. USE AT YOUR OWN RISK if you use a PACEMAKER, INSULIN PUMP, OR DEFIBRILLATOR etc...Thanks DO NOT clean in an UltraSonic cleaner, as it will weaken the strength of the magnets. Weight: 0.62grams each DO NOT clean Magnetic Claps in ULTRASONIC cleaners as it will reduce the strength of the magnets.