The MK516 is a replacement CB microphone for the Uniden PC68XL and PC78XL radios. It is also the replacement mic for the PC68LTW and the PC78LTW. If your coiled cord is kinked and untamed or your microphone is no longer working right this is a great factory replacement part for you Uniden Citizens band radio. This 4 pin microphone is also compatible with many newer CB radios wired with Cobra/Uniden connectors. The MK516 is a good looking Uniden OEM dynamic mic that is plug and play compatible with your Uniden CB radio. This mic also fits all newer CB radios wired 4 pin Cobra/Uniden.