These adaptors allow for a plug and play installation of the Injector Dynamics ID725/850/1000 injectors in to cars with Denso injector connectors. These are priced individually.
Some of the models that use the Denso connector style are:
Nissan VR/VQ Engines
Subaru Turbo Models
Mitsubishi EVO X
Mazda Miata
Mazda RX-7
Toyota Supra