|Output weight||7800 kg|
In coastal engineering, conventional concrete blocks tended to become dislodged over time by the force of the crashing ocean against them. Tetrapods were developed as armour unit on breakwaters. The shape is designed to dissipate the force of the incoming waves, and displacement is reduced by allowing a random distribution of tetrapods to interlock.
The available sizes vary from 1,0 til 7,8 tonnes.