Operable sash move smoothly with a constant force coil spring balance system that never needs adjustment.
On Double Hung windows, sash slide easily up or down due to a constant force coil spring balance system.
Interlocking design of the meeting rail securely fastens sash together.
To assist with quick installation, Series 500 windows are available with wood or Quick Trim™ cellular pvc jamb extensions. Choose either 4-9/16″ or 6-9/16″ construction.
The U-channel spacer system, more efficient than conventional spacers, moderates outside air before it hits the inside sash.