Yamau Holdings Co Ltd Is a Japan based company engaged in engineering, manufacturing and selling concrete products. It offers civil products, including river rocks, type retaining walls, sewer drains, functional concrete, and dam related products. The concrete product portfolio of the company comprises Aquapond S-type, Green rock, Kagomasu, Tameloop, Loop Arch, FA Box, Precast box culvert, fire protection water tank, power rock, super cliff, three side channel and YT channel, among others.