Hot Wheels Premium
Premium is collector-focused retail (about $7.00 to $15.00 for 1:64), commonly Metal/Metal with Real Riders. Pack size (2-Pack, Display Set) belongs in Type (product_type), not Category.
Category Rule
On SmartWheelers, Category is the price tier only. Named product lines belong in Series (and Sub Series when needed), not Category.
Series Under Premium
Boulevard; Car Culture; Car Culture 2-Packs; Cool Classics; Dragstrip Demons; Entertainment; Fast & Furious; Formula One Collection; Hot Wheels Delivery; Hot Wheels Garage; Hot Wheels Heritage; Hot Wheels Racing; Nostalgic Brands; Pop Culture; Premium 1:43; Premium Display Sets; Team Transport; Vintage Racing