It was available in CenturyLink/Qwest areas. Not sure about now, a lot of the loop products have been grandfathered recently.
https://www.centurylink.com/wholesale/pcat/fcp.html
I was one of two providers in their 13 state region that used it. It was really successful and let us put in ADSL and then Ethernet over Copper in business parks.
As a CLEC, they could place DSL equipment in the incumbent carriers (mostly Pacific Bell/ATT, but Los Gatos Telephone company was absorbed by GTE/Verizon and I think sold to Frontier) and use the existing wiring to run DSL. In silicon valley, this doesn't offer great coverage; to get reasonable line lengths, you need to be in the telephone company's remote terminals and that's not available to CLECs.