Please include the following in the "special instructions" section during checkout, or email us after you place your order at email@example.com:
~Choice of Charms
Size: approximately 0.3 x 0.5 inches
stainless steel, 18k gold plated
13 inches with a 2 inch extender to allow a 15 inch length. If you would like a different length, please include this in your customization instructions.