5.5mm, 6mm spring ring These are 1.5x stronger than our 4.5mm ones.These will lift 565grams before separating.Absolutely the strongest we have found in this size range. White is listed, item 265752109572 This clasp is: 5.5mm diameter X 17.5mm, including 6mm spring ring 7/32" X 11/16" a dime coin is 17.5mmComes with Heavy Duty 4mm 20ga open jump ring made from 3/4 hard wire. We won't sell them without a jump ring, as there pretty much aren't any clasps that would attach to the opening attached to the magnetic section. In our opinion, suitable for chains up to 40grams. You be the judge for yourself. No hassle returns. 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 Weight: 1.10grams each DO NOT clean Magnetic Claps in ULTRASONIC cleaners as it will reduce the strength of the magnets.