Irvine Company has officially opened 400 Spectrum Center, its latest high-rise office tower at the Irvine Specturm.

The 21-story building - alongside its twin at 200 Spectrum Center Drive - ranks as the tallest building in Orange County, rising to a peak height of 323 feet above ground.  Inside, the boxy glass tower from Pei Cobb Freed features 426,000 square feet of office space, as well as very tenant amenities.

400 Spectrum Center is opening 40 percent pre-leased, with cybersecurity firm Cylance taking 135,000 square feet of space across six floors, as well as rooftop signage.  Other tenants within the building include Kieckhafer Schiffer & Co, LLP and CrossCountry Mortgage, Inc.

The project's completion comes one year after the opening of 200 Spectrum Center, which is currently 93 percent leased.  The tower's signature tenant is Mazda North American Operations.