- Match your windows (lower sash) visible glass size (width & height) to the chart
- Works with Perma-Shield Narroline Double-Hung Windows manufactured from 1968 to Present.
- Sash balancers are metal boxes that contain a nylon cord under tension.
- The balancer number is a code for the tension and the cord length.
- If you replace one balancer you should replace both balancers.
- Match your windows (lower sash) visible glass size (width & height) to the chart
- Works with Perma-Shield Narroline Double-Hung Windows manufactured from 1968 to Present.
- Sash balancers are metal boxes that contain a nylon cord under tension.
- The balancer number is a code for the tension and the cord length.
- If you replace one balancer you should replace both balancers.