Are you looking for FS6Uconnector? If you are then I know of a website on where to buy it. The website is compressionconnector.com and you can easily visit the website by clicking on the link that I embedded in this post (or else you can also copy and paste it on your browser).

FS6U connector fits on almost any RG6 cable even quad shielded RG6 along with the CPLCCT-SLM. Aside from FS6U connector, the website is also selling starter kits, in case you want this one. The website is pretty easy to browse, you can easily find what you’re looking for hence the category was divided into options that will let you click on the specific list of items right away.