PARIKHS LuxLock World's most secure USA Patented Replacement Earring Back in White-Yellow-Rose Gold PARIKHS LuxLock  World's most secure USA Patented Replacement Earring Back Pair in 18k Yellow gold (Patent # US8365369). Easy to handle and provides close and secure grip. It is used for Friction Back stud. It's surgical stainless steel mechanism guarantees strength.