OTC Tools CEA-02 Assorted Cap Plug Kit OTC Cap Plug Kit These caps and plugs are used to seal the intake ducting of an automotive engine being tested with OTC's No. 6521 or 6522 Leak Tamer 16 piece set includes multiple sizes to fit most applications Durable construction will withstand repeated use Molded in yellow for high visibility, making them easy to find and less likely to be left in place after testing