In this manual the 3-bladed VIRYA-1.04, electricity generating windmill, is described. The generator of this windmill is made of a Shimano Nexus hub dynamo type DH-2R40 or another type with similar flange dimensions. It is expected that, together with the detailed drawings, the windmill can be manufactured in a simple workshop. The drawings of the VIRYA-1.04 windmill are numbered 1301-00, 1301-01 and 1301-02