HD is Gateway’s shorthand for Hyper Diamond, and it’s listed here separately because a disc on this site carries the short name. It’s a real line, not a firmness grade: more opaque and grippier than plain Diamond.
It’s the Gateway premium blend for feel, sitting in the grippy opaque class alongside Innova Star. One mould is listed under the HD name.
See Hyper Diamond for the full line. These two entries are the same plastic and will be merged.
