Air Filter, Element/Radial Seal Outer, Length 18 5/8 In, Outside Dia 12 31/32 In, Inside Dia 6 13/16 In RestrictionsNote: More filters are available on DrillSpot.com . FiltersAirMetal wrapper surface area is 73% open for minimal air flow restriction. PermaPleat design creates built-in pleat spacing and prevents bunching. Radial Seal filters have seal gaskets made of a special urethane compound that will not degrade due to temperature or changes in restriction or vibration.