Bolt seals are high-strength security seals used on shipping containers, railroad and air freight containers. The solid metal core head and a locking cylinder that is encased in shock proof plastic makes for a high level security seal and an efficient tamper deterrent. Liaoseal provides a selection of high security bolt seals. Our line of bolt seals are designed for securing ISO containers and high value cargo shipments, C-TPAT Compliant , ISO 17712 - These bolt locks have dual serial numebring on them.