What are Progressive Suspension's 'STD Duty' vs 'Heavy Duty' shocks

Paper gasket with copper fire ring

as in use with regular LED headlamps

02-07  V-ROD WITH 1 INCH AXLE (FRONT/REAR)

BLUE LIGHTNING AIR FILTER ELEMENT 1988-22 XL Belt Drive Kits What are Progressive Suspension's 'STDEconomically priced but high end quality and offering superior flow, longer service intervals, better flame resistance and will last much longer than comparable foam or paper type filters. Filter elements are constructed with 4 layers of ribbed pre oiled cotton filtering media. This will maximize air flow but still provide adequate filtering capacity, equalling the best performance filters on the market. Very durable through the use of coated wiring