The fuel rail ports are tapped for 8AN ORB
The Radium Engineering high flow primary fuel rail is for the 13B-RE and 13B-REW rotary engine found in the 1990-1995 Mazda/Eunos Cosmo and 1992-2002 Mazda RX7 FD3S. The aluminum fuel rail is anodized black for compatibility with all popular fuel types including E85. Manufactured with a large internal bore, the fuel rail can support all necessary engine power requirements
Insulating phenolic spacers and washers are included with stainless steel hardware to prevent thermal energy from conducting heat into the fuel.
The included 14mm lower injector seats (shown above) were designed specifically to be compatible with or without the OEM diffusers in place. They feature Viton O-rings making them suitable for boosted applications
Below are some of the many fuel injectors that are a direct fitment with this fuel rail:
Injector Dynamics ID1050x-34-14-14
Injector Dynamics ID1300-34-14-14
Injector Dynamics ID1700-34-14-14
Injector Dynamics ID2000-34-14-14 
NOTE: Fuel Injectors are NOT included and must be purchased separately.