Andersen TW2446 (Lower Sash) Sandtone Exterior and Natural Pine Interior High Performance LowE4 Tempered Glass - No Grille Grommets Category_Perma Shield Gliding (1971-1991) It also adds fade protection

It also adds fade protection and water spot reductions due to it's special coating

Andersen TW3842 (Upper Sash) White Exterior and White Interior High Performance LowE4 Glass (1992 to May 2010) Works with 400 Series Tilt-Wash Double-Hung Windows manufactured from 1992 to May 24

Andersen 2846 Narroline Double Hung Upper Sash White Exterior with White Interior Works with Andersen Narroline Double Hung 1968 to 2012

This sash has an unobstructed glass size of 15 inches wide by 19 15/16 inches high high

High-Performance Low-E4 glass replaces previous versions of Low-E glass

Andersen TW2446 (Lower Sash) Sandtone Exterior and Natural Pine Interior High Performance LowE4 Tempered Glass - No Grille Grommets Category_Perma Shield Gliding (1971-1991) It also adds fade protectionAndersen TW2446 (Lower Sash) Sandtone Exterior and Natural Pine Interior High Performance LowE4 Tempered Glass No Grille Grommets This Sash has no grille grommets, any interior grilles for this window will need to have the chisel style plungers. This sash has new High Performance Low E4 glass and replaces previous versions of Low E glass. High Performance Low E4 tempered glass provides outstanding insulating performance in both heating and cooling