... joint metal hoses BL5, L5 (Seamless spiral, ring hose, tongue lap-joint nuts at two ends) ... type quick coupling metal hoses YK, R1K (Seamless ring pipes, melon-type coupling at two ends)Melon ... coupling metal hoses LYK, LR1K (Longitudinal spiral, ring pipes, melon-type coupling at two ends)H ... PTFE pipe, Teflon pipe, PTFE stainless steel wire pipe, Teflon stainless steel wire pipe PTFE stainless steel ...