Zero Line is Latitude 64’s baseline putter plastic, sold in Soft, Medium, and Hard so you pick the firmness. It’s the parent of Westside BT and Dynamic Discs Classic.
That’s the range to choose a putter feel from. Hard for a consistent release, Soft for grip and a dead landing. Two moulds are listed on this site.
It wears the way putter plastics do, and it isn’t a driver plastic. Zero Pro is the tougher version.