This exhaust porting template kit includes one aperture template and one aligning jig. The aperture template is version EP1A, which is recommended for 84-91 RX-7 Non-turbo 13B streetported engines using 87-91 TurboII Rotor Housings. We do not recommed the use of NA housings due to the exhaust baffle restricting flow. Other aperture templates are available for different engine/porting combinations.