Quick Coupling: 1) Type: A, B, C, D, E, F, DC, and DP; 2) Size: 1/2", 3/ ... water, etc. 1) Material: brass 2) Type: A, B, C, D, E, F, DC, and DP.3) Size: 1/2", 3 ... face of groove and great resistance to vibration. 5) P. S. We are the qualified member of NFPA. Brass Quick Coupling