The Starter Package comes with everything you need. The Large ORIGINAL PetQRTag is approximately 1-1/4 inches x 1-3/8 inches. The Small ORIGINAL PetQRTag is approximately 7/8 inches x 1 inch. Both ORIGINAL PetQRTags include one 20mm nickel plated split ring to fasten the tag to a collar. A unique QR Code will be engraved on the tag. The back of the tag will include your pet's webpage address and short instructions to scan the QR Code that will take the viewer directly to your pet's page. An activation code will provided to with the tag to claim your pet's page. Updating the pet is simple and can be changed whenever you wish.