With white/bluish backlight

Fits: > 80-90 5-speed Big Twin

OEM replacement reference 63860-50

dept to mount hole 100mm

PS, 444 series shock set. 13". STD Duty. Chrome Dyna 91-17 Motor & Förgasare With white/bluish backlight444 series shocks Best. Comes with FST (Frequency Sensing Technology) which dynamically adjusts damping, according to road surface. Top mount threaded hand adjustable preload. 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