Galvanized steel chain (rust-resistant) for durability. Use stainless steel in coastal areas for extra corrosion protection.

Measure the exact width at the top, middle, and bottom of the window opening, then use the narrowest measurement. For height, measure from the top of the window frame to the sill at both sides and the center, using the longest measurement.

Use outside mounting that extends beyond the window frame by at least 2 inches on each side. Add side channels if available, and ensure the blind touches the windowsill when closed.