857 Series - Commercial Security Standard Features Meets Commercial Security Specifications 2 Inches Thick Steel Stiffened Core 14 Gauge / Plus Flush Prep or 16 Gauge Top Channel 14 Gauge Bottom Channel Fiberglass Insulated Between Stiffeners 4" Stiffener Spacing 14 Gauge Face Skins Fire Rated up to 3 Hours Sizes from 2068 to 4080 Rugged Perimeter Channel Construction For more detailed information, please see the link below. Find technical information here >>