noob question about silicone hoses and air filters

  1. #1
    does the silicon go inside the filter opening or on the outside? and when im shopping for silicon bits is ther measurement the inside or outside dimater?
    just got an email from spoox saying the diameter is 64mm at the filter end and the inside diameter of my filter is 67mm
  2. #2
    Silicone is normaly internal diameter
    filter depends on the make