A plug connection kit for connecting a branch line to a through line, comprising a plug housing and a socket housing that enclose contact inserts. Flexible cable ends are molded onto the plug housing and socket housing. The plug housing and socket housing are each manufactured by casting plastic onto a base body with the contact inserts and flexible cable ends connected thereto inserted, thus forming a solid one-piece plug and a solid one-piece socket. The female and male contact inserts are electrically connectable to one another in a contact area between the plug housing and the socket housing. The plug connection kit also includes a sealing sleeve that encases the plug housing, the socket housing, and the contact area between the two housings in order to protect the plug connection kit from penetration of water and/or dust.