Tremron RW0-3187-G2200-A 4" x 18" x 12" Santa Fe Keystone Compac® Cap - An industry favorite, Keystone Compac III combines unrivaled aesthetic options with cost saving versatility and proven wall performance. Trusted by architects, engineers, and contractors worldwide, the Keystone Compac III utilizes the proven Keystone pin connection system. Due to the improved design, Keystone Compac III delivers all of the structural security people have come to expect from the Compac unit.