There is a handy Velcro strap for attaching to your belt or webbing so others never have to go searching. Valhalla has designed these snap hook tags for every blood type. Features: BENEFITS OF THE VALHALLA BLOOD TYPE TAGS Available for the following blood types: A+, A-, B+, B-, O+, O-, AB+, AB- The POS and NEG indications are spelled out on the key chains Use the velcro strap can for attaching the tag to your belt or webbing platforms Available in Multicam Low price points means you can buy the tag, take off the Snaphook and use it on your rifle sling Letting first responders know your blood type without you having to utter a word could save your life in an emergency.