We can't find any source for this item (quests reward, drop, etc). It's highly probable this item is not obtainable right now.
100%
Random Attribute if Gear Score is 470+ is wrong, got a 597 without the extra "100%" attribute, only with frost conditioning that already comes with by default.
@AlephZero this item is bugged. It actually does have 2 extra attribute buckets (instead of perk buckets), but if you check the buckets, the attributes have a 0% chance to roll (because you already have an attribute).