Its not a breeder or seedbank, clone only strains are only available as clones. Mostly they are special selected phenotypes of a commercial strain, or old classics who was keeped by someone somewhere...

Gravity floated its way to T.H. Seeds on a long journey. In 1999 it started her in Amsterdam in limited batches from Neville and Shanti Baba. This multi hybrid indica proved itself by being kept alive for years only to return to Amsterdam, this time as a clone...Nevil: Gravity was a 4 way indica I made for Sensi using an extremely potent Hash Plant x NL1 as the mother. There were a couple of versions. The effect was seriously heavy. Gravity!