The simple design of this rectangular dog charm necklace makes it universally popular regardless of age or gender. The dog tag measures 18mm high x 8mm wide x 1mm deep and has room on each side for 4 engraved characters. This is threaded along a fine box chain with a 1mm curb using the jump ring fastening. You can select the appropriate length for this chain using the drop down menu. We have lengths from 14 to 22 inches available. They all fasten with a spring ring clasp.