Sterling Silver dog tag is 20 gauge thick and measures 16mm wide by 29mm tall. Includes 18" sterling silver ball chain necklace. Can be made as a Keychain instead. Since these pieces are stamped and personzalized, they are non-returnable unless we have made an error in manufacturing such as a misspelling. PLEASE ENTER YOUR PERSONALIZATION INSTRUCTIONS AND YOUR SELECTION (Necklace or Key Chain) IN THE COMMENTS SECTION OF THE CHECKOUT PROCESS.