Designed for Angled Applications. Outside Pre-Filter May Be Used in Dry, Dusty Conditions or Oiled for Wet Conditions. Inner Filter Must Be Oiled. Proper Oiling Will Not Affect Air Flow. High Capacity Design. Inner Diameter (Inches/mm): 3"/76mm. Foam Length: 6". Mikuni Size: 36-38. Please Note: The Image Displayed Is Representative of UNI Flex Core "Sock" Filters, but May Vary Depending on Your Specific Model.