2). All-UPVC multi-chamber design and multiple weather-stripping deliver amazing energy performance.
3). Interior glazing bead: Key design component for withstanding 220 mph (350 km/h) winds.
4). The most internal chambers: Outstanding insulation, noise reduction, thermal efficiency, and strength. Ranked Number 1 out of 22, 000 windows tested by the (US) NFRC for energy performance.
5). Full-size, double-walled handle bead: Remarkably sturdy, built for years of tough use.
6). Mounting hardware installs through at least 2 UPVC walls for secure, time-tested placement.