Metal security seals usually fall within the categories:
bolt seals, cable seals, wire, padlock or fixed length seals.
Bolt seals are used to secure high value cargo, cross border shipments, trailers and container door latches. They are generally closed by hand, (by pushing the seal body and head together), and opened with the use of bolt cutters. This gives a strong and secure seal for transportation, while remaining convenient for staff in ports and warehouses.
Cable seals allow for more versatile usage, having variable lengths locking mechanism that are determined by the cable length. They are frequently aluminum or zinc. Applications include sealing trucks and rail cars that transport valuable cargo.
Wire hasp and padlock seals are made from a combination of metal and plastic; these seals provide ideal tamper evidence for smaller aperture applications like utility meters, drums, containers and airline carts.