The EcoTherm 4000 line unites elegance and performance in a single, highly-efficient system. Engineered for strength and durability, with high-end features typically found only in the most expensive premium lines, the 4000 vinyl replacement window delivers superior value.
|HP Low E||0.34||2.94||0.27||0.51|
|Supra Low E Argon||0.30||3.33||0.27||0.51|
|DOE R5 Triple Glass Package||0.21||4.76||0.22||0.40|