Abstract: A cylindrical housing has a flange at an exterior end, male threads in an external surface remote from the flange, and a small axial hole, and female threads in an internal surface remote from the flange. A disk shaped fastener has internal threads rotatably supported upon the male threads of the housing. The fastener rotates to secure a prosthetic limb adjacent to the flange for operation and use and to allow separation of the limb from the housing. A cup-shaped end plug has a side wall with male threads receivable in the female threads of the housing and an end face with an axial opening. A plug with a pull string is positionable within a partly spherical surface adjacent to the interior end of the housing. A coil spring is positioned between the end plug and the spherical plug.