Delta 2 is a separate Lone Star plastic, not a second version of Delta: stiffer, smoother, and more durable. Opaque, premium tier. Ten moulds are listed in it.
That’s the Lone Star plastic for holding a mould’s flight. It sits in the grippy opaque class but at the firm end of it.
It’s less tacky than Delta or the Victor blends. Buy it for lifespan, not feel.