This stock bolt is used to attach the rudder pintle or gudgeon to the rudder head. As used on the following boats: RS Tera - Old style Seasure rudder stock. RS Quba - Old style Seasure rudder stock. RS Feva - Old style Seasure rudder stock. RS Vision, RS Vareo, RS100, RS200, RS400, RS500, RS700 and RS800. M5 X 12 CSK. Includes M5 washer and nut.