How to measure your bracelet size: 1: Use a measuring tape or a piece of string to measure the size of your wrist. 2: Add 1" to allow room for comfort and shrinking. Example: If your wrist measures 7", choose 8" when ordering your bracelet. Tight wrist mesurement/Recommedned bracelet size: 15-16cm/17cm(6.7") 17-18cm/19cm(7.5") 19-20cm/21cm(8.3") How to open the snap clasp: 1. Press the concave position by using your fingernail. 2. Take out the head part of bracelet from the groove (just one side). 3.Put the beads into the bracelet. 4.Put the head part back to groove and then close it.