A medical device lead includes a proximal connector configured to couple the lead to a pulse generator, an insulative lead body extending distally from the proximal connector, and a conductor assembly extending distally from the proximal connector within the lead body. Connection contact pieces are provided at both ends of the line connector, and can be brought into engagement by vertical introduction into the plug sockets located on the upper edges of the base housings, whereby the electrical contact is produced between the first bus bar and the second bus bar. A coupling adapter is disposed coaxially within the housing bore and fixed to the wave generator and supported in the housing by a bearing which is press fit onto a bearing surface of the coupling adapter. The unlocking button includes an unlocking retaining pole is inserted into an unlocking sliding groove of the casing.