Known in the UK as Rockbags, Japanese company Kyowa’s Filter Units, are a versatile product simply made of mesh net and rocks. When deployed the rock filled bags prevent flood and bridge scour without destroying the environment. They protect marine cable and pipeline installation by conforming to existing terrain. They are easy and cost effective to deploy. Rockbags / Filter Units fit into the environment perfectly because living things such as small fish and plants can live in the interstices inside the Filter Unit.