Bolt seals can come in two distinct forms, one flexible and the second rigid. Flex seals such as the B-11 are far safer to remove as they are taken off by a cable cutter, not a bolt cutter.  The clipped portion of the flexible seal - which is often left on the ground - will not flatten tires; laser-engraved, easy-to-read numbers makes it ideal for applications that use conventional bolt seals.  The B-03 tandem steel bolt seal comes as a matched, engraved set of barrel and shaft, both laser-engraved with a sequential number; they can also be bar coded and custom marked, if desired.