Medical Dog Tag . This tag is engraved with the on front and your emergency information engraved on back. Alert Medics to your medical conditions and allergies. Don't leave home without this sturdy aluminum dog tag. These tags are diamond etched which permantly engraves your information. Medical dog tag set includes 1 engraved dog tag 1 30-inch chain and 1 black silencers. The backside can be engraved with up to 5 lines and 20 characters or spaces per line.