Originally Posted by Demothen

MB used a "cigar lighter" in my w123 which is a little bit larger than a modern 12v socket. I think i have had good luck with https://www.amazon.com/dp/B00M6QODH2/ref=cm_sw_r_cp_api_q0S2xbSDY4762. But I can check tonight to be sure which one I use.