This is for 3 pieces, the actual registers/ outlets are not included.
 
73-79 Ford dash vents are three different sizes and all 3 are inconveniently different. This makes it difficult for installing vintage or other similar aftermarket systems. These adapters allow you to use common 2.5" round tubing on all three of the dash outlets.
 
These are designed and printed right here in the USA. They have a very snug fit and should give years and years of excellent service.