The FireKing® Model 635 fire-rated rolling service door offers superior protection wherever a listed insulated fire door is required (max. width 24’; max. height 24’). The Model 635 insulated rolling steel door serves as a thermal barrier, ideal for applications which require separation due to climate control requirements. The insulation used in this door offers added energy efficiency (R-value of 4.5), sound transmission control (STC 21), and the mineral wool utilized in the slat insert meets the Smoke and Flame Index of 5.