Allows for optimum rebound and compression performance for any given rider weight, personal ride quality preference, and personal riding style. REVO coils provide improved plush ride quality, control, and resistance to bottoming-out. These shocks are adjustable by hand with no tools needed. Finished in Black Type III Hard-Coat Anodize Spring rates produce superior ride quality and performance REVO coils provide improved plush ride quality, control, and resistance to bottoming-out Extended coil length has larger "sweet spot" without increasing overall shock length Adjusts by hand with no tools needed Available in 13" and 14", standard or heavy-duty applications Easy installation and alignment, provided by spherical bearings on both top and bottom 35mm monotube construction Deflective disc valve stacks Balanced/Matched piston and base-valve design specific to motorcycle applications Low friction sealing system and PTFE based sliding bearings for improved performance and feel Seven external knob adjustments allow fine-tuning of rebound and compression Nitrogen gas bladder design allows ultra-fast response and stiction-free movement Light to heavy riders can fine-tune ride preference Aggressive to casual riding styles can tune to desired quality or personal preference; Note FL: Heavy Duty applications are recommended for 500lb. + rider and passenger weight; Note Dyna, FXR, Sportster: Heavy Duty applications are recommended for 250lb.+ rider and passenger total weight. Also consider Heavy Duty if the majority of your riding is 2-UP, stunt riding, or aggressive riding style.