This is an image of an Ameristar steel fence that is equiped with the Stalwart Post and Rail system.
The Impasse posts and horizontal rails accept the Stalwart integrated cable system for added perimeter security. This combination has successfully tested to the U.S. Department of State's K8 Anti-Ram rating, stopping a 15,000 pound truck traveling at 40 mph within 1 meter of the fence line.