Link to Tulista aka. Haworthia https://en.wikipedia.org/wiki/Tulista

With out flowers to have narrowing down which succulent genus these belong to, I could only speculate for now. Perhaps something in the Haworthia genus (?). According to sources, this genus recently has divided into 3 genera, the Haworthia, the Haworthiopsis and the Tulista. If this is in these genera, I’m unable to tell if yours is species, subspecies, hybrids and whether it is a clumping or stem type. Check out these included links for more information. When your bloom and you still don’t know, make new post with photo of flowers. Click on images to enlarge. Best wishes! https://en.wikipedia.org/wiki/Haworthiopsis