R-5 Rated Double Hung Windows

The Series 4601 is MGM's premium R-5 rated replacement double hung featuring a fusion welded main frame providing added strength. Custom made to your measurements, the Series 4601 will meet the most challenging of remodeling requirements. These triple glazed windows with LowE on the #3 & #5 surfaces and argon gas meet federal requirements for the R-5 program. For a U.S. Department of Energy fact sheet on the new R-5 program click: R-5 fact sheet