This part is used to UPGRADE your existing RFC-89-TN, carside "nipple" to allow it to accept the "LM" Lock mechanism verison of the RFC-89-K-LM coupler, to allow you to gain the enhancements of the latest products, without having to change your complete carside "Nipple".Please note: You will need to purchase seperately 12 x M5x5 Grub screws. For details on the conversion see our fitment instructions PDF document on this page.