For R1234yf refrigerants. High Side R1234yf Coupler (Red): M12mm-Female x 17 mm. Low Side R1234yf Coupler (Blue): M12mm-Female x 14 mm. R1234yf COUPLERS x2. Usage & Compatinility: The professional automotive high and low pressure quick couplers adapter for R1234yf refrigerants, AC manifold gauge, diagnostic check, recovery and evacuation work.
