- LARGE SIZE - This lock bracelet is 18cm in circumference and 6cm in diameter,fits 7 inch wrists.We recommend that you measure your wrist before buying to avoid it not fitting your wrist. - LOCK KEY NECKLACE SPECIFICATIONS -necklace pendant size :18*23mm.chain lenght:50CM. - Lock Bracelet and Key Necklace - Unique couples design with a heart lock bangle & shield key necklace. Romantic matching lovers jewelry symbolize that only you have the key to open my heart. - COUPLE JEWELRY - Romantic symbolize that only your key will open up my heart lock. Best gifts for girlfriend and wife,daughter on valentines day, Christmas, birthday, wedding, anniversary. Never Give Up to Love You. It means you'll always be together forever. - MATERIAL - High quality titanium steel,use Laser Cutting and Polishing Technique,anti-allergic, and are not easy to corrode, rust or be contaminated by water.can last longer than other jewelries. - HOW TO OPEN AND CLOSE - Key necklace and lock bracelet couple bracelets set is very delicate jewelry, so it takes a little skill to open and close. Align the key with the lock core of the bracelet, rotate it 90 clockwise, it is opened; align the sides of the bracelet , fasten it tightly and it will close