These are machined billet adapters that go over the top of the shorter new style injector to allow then to fit in applications that use a standard 60 mm injector and a std 14mm o ring.
There are 1000's of applications that these can be used for. Example: LS2 to LS1 or LS3 to LS2. Any 38mm injector to STD 60mm
Part Number: FICHALF14MM