Fast Eddy. No. 56 intake leak tester, 4 boltThis is an intake test plate; complete with air fitting. Used to make sure you don''t have intake leak issues. The test plate bolts to the intake manifold; make sure to collapse the intake pushrods; and use a vacuum hand pump to see if the system holds vacuum. If the system doesn''t hold 10 inHG for 10 seconds or longer; you have a leak that you need to deal with. You can then switch over to positive air pressure to more easily find the leak. USA made.