Devices conforming to this drawing are intended for use when military specifications do not exist and qualified military devices that will perform the required function are not available for OEM application. This drawing is intended exclusively to prevent the proliferation of unnecessary duplicate specifications, drawings, and stock catalog listings. When a military specification is created and the product covered by this drawing has been listed on QPL-19500, this drawing will be inactivated and will not be used for new design. The QPL-19500 product shall be the preferred item for all applications.