PS, Model 944 shock set. 13". Heavy Duty, Black

944 series - Best.
For Touring models. Designed with dual springs to give a 1" lower bike while riding or on the side stand. Still retains full travel and length for uncompromised smooth cruising. Comes with FST (Frequency Sensing Technology) which dynamically adjusts damping, according to road surface. The 12.5" Ultra Low version drops Street Glides 1" and a 2" drop for most other Tourings, with minimal loss in ride quality.

What are Progressive Suspension's 'STD Duty' vs 'Heavy Duty' shocks?
If you are a lightweight rider with a lightweight passenger, STD Duty is probably your best choice, heavy duty shocks will give you a harsh ride. For Big Guys & Gals with a lot of baggage, Heavy Duty springs are the way to go. Heavy Duty is not better, it's different.
Heavy Duty shocks or springs are recommended to be used on motorcycles that are operated at or near the manufacturers maximum load rating over 50% of the time.