Definitive Technology ProMonitor 800 Bookshelf Speakers (Pair Black) & Definitive Technology Pro-Mount 90 - Pair (Black) Definitive Technology ProMonitor 800: Equipped with one 4.5-inch cast basket bass/midrange drivers coupled to one 4.5- Definitive Technology ProMonitor 800:Equipped with one 1-inch pure aluminum dome tweeter Definitive Technology Pro-Mount 90: Articulating wall mount bracket accessory for Definitive Technology speakers Definitive Technology Pro-Mount 90: 2 per pack