I'm not aware of any 20ml bottles of sust currently being produced, but I know of an underground lab that is preparing to release sust in 10ml and 50ml. Like Karachi said, there are some similar blends, but it's not sust.
For it to be "Sustenon" it has to be an Organon product, and they don't make any mult-dose test products that I'm aware of. However there are many other labs that make a Sustenon blend under different names.
Seeing how it's 20ml I'd bet it's either a Vet, or more likely a UG lab product.