What damper model should I use in coastal regions (salt air)?

Model SW-155 (Opposed Blade) and SW-156 (Parallel Blade).

The dampers are constructed of clear anodized extruded aluminum frame and blades material, hollow aerodynamic shaped blades with end caps, linkage is aluminum and 316 stainless steel, bearings are two parts bearings with the inner made of acetal copolymar and the outer part is polycarbonate, blade seals and jamb seals are santoprene (TPV).

These materials hold up to salt-laden air and other chemicals.