Compared with barbed wire, wall spikes take up less space, cost lower, but the firmness is stronger, deter effect is greater, used on gate, building wall, fence.
Fence security spikes and toppings
Ultimate Extra SR1 High Security Fence
Guide for fence security and proofing - Pest Control Worldwide - A
Razor Spikes, Wall Spike, Security Fencing Spikes, Bird Spikes
Fence and wall security toppings – what is the most effective
ArmaMesh358 - Secure Guard 358 Mesh Security Fencing
Wall Spikes on Gate, Building, Fence for High Level Security Fencing
Viper-Spike® high security fence / wall topping
Prison Fence – High Security Fence to Prevent Criminals Escaping
Clear View Fence Pictures: A Comprehensive Look at Components
Stegastrip® Fence Wall Spikes Garden Security, Intruder deterrent