Our cross border security seals have an enhanced performance tamper evident material that shows a clear void or open message when the label is lifted. Initially developed for use on the doors and hatches of aircraft when they are parked overnight or in flight, however these cross border security seals are ideally suited for use on most surfaces. This product gives visual evidence of tampering or illegal entrance on aircraft, vehicles, doors, sensitive equipment, lockers, containers, restricted areas, etc. These cross border security seals are great for travel.