... external appearance. 7.JINYOU 304stainless steel sleeves sizeSingle Single flared stainless steel sleeve Size DIA 12,14,16,18,20,25 ... ,32MM Double flared stainless steel sleeve Size DIA 12,14,16,18,20,25 ... . Used for fastening, joining, or reinforcement ,such as for facilities of cold water, sanitary hot water, and heating ect. Stainless steel ferrule for stainless steel ...