Known in the UK as Rockbags Japanese company Kyowa’s Filter Units, are a simple versatile product made of mesh net and rocks. When deployed they function to prevent flooding and bridge scour damage without destroying the environment. They protect marine cable and pipeline installations by conforming to existing terrain and anchoring to the seabed. They are easy and cost effective to deploy. the Rockbags fit into the environment perfectly because living things such as small fish and plants can live in the interstices inside the Units.