PS, 422 series shocks. STD to -2". STD Duty. RAP. Chrome

RAP adjustable. 
422 series - Better. 
Two inches, standard to 2" lower, of ride height adjustment and adjustable preload. 
High pressure gas system in a dual coil shock system. 
The shocks include a new fill valve to replace the stock one. 
Also available in the RAP (Remote Adjustable Preload) series, which comes with the added convenience of a Remote Adjustable Preload, located behind the left passenger peg, for easier accessible adjustments. 

What are Progressive Suspension's '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.