Razor mesh
razor mesh is a form of razor wire that is welded into sheets of mesh with large, diamond shaped openings. The wire the mesh is made of is razor wire.
These sheets are usually galvanized and often tied to the inside of another kind of fencing, so that only when someone tries to scale the fence will they come into contact with the barbs.
Because razor mesh is so hard to climb, it's often used in anti-climb or non-scalable fence systems.