#4 MJIC x 1/8" MNPT connection. Described by Coltri as "CONNECTION 1/8 NPT - 7/16 6MM TUBE [RACC.1/8 NPT 7/16 TUBO 6]." For additional information on this kit, see Parts List page 20-36 located under the User Manuals tab.
Nuvair offers authentic parts and equipment manufactured by Coltri Compressors. Beware of inexpensive aftermarket imitations labeled as "replacement," "OEM equivalent," "compatible," or "alternative," as they are not made by Aerotenica Coltri S.p.a. Due to size, weight, or specific requirements, some Coltri products may not be available for online purchase, and others may have extended lead times. To confirm compatibility with your existing equipment or to ensure the product meets your needs, please contact the Nuvair Sales Team for ordering assistance by email or phone.