Besides KFORTS high security performance, TR system complies with all requirements in building physics up to highest level. It features a slim frame, a concealed sash design, and a wide visible area. Resistance against wind load Water tightness Air permeability Technical parameters: ≥ 16kpa/m ³ (1800 * 1500), Technical parameters: ≥ 700 (PA), Technical parameters:The unit seam length index value is ≤ 0.5m ³ (m · h),The unit area index value is ≤ 1.4 square meters (m · h),Level: 8 (max). Air permeability Sound Insulation Standard: EN673 Standard: GB/T 8485-2008, Technical parameters: 1.87-2.15 W/(㎡· k) Door: 2.158 W/(㎡· k) Window: 1.875 W/(㎡· k) Curtain Wall: 1.873 W/(㎡· k) Technical parameters: ≥ 45 (dB (A)),