1)Suitable for any tubes. 2)Easy steps to take tubes off. 3)Once inserted to the nut, the tube would not easily loose4)Nickel-plated metal body ensures anti-corrosion and anti-contamination 5)All R and NPT threads are pre-coated sealant 6)Quick and simple tube insertion 7)Compact, lightweight design 8)Advanced, well-proven tube retaining system 9)Re-usable thread seal PC,POC,PL,PLL,PLF,PCF,PB,PD,PX,PKB,PH,PHF,PMF,PU,PE,PG,PEG,PGJ,PLJ,PYJ,PGE,PW,PLGJ,PIJ,PKJ,PM,PKG,PIG,PP,PZA,PKCOMMON Size:4mm X M5 4mm X M64mm X 1/8" 4mm X 1/4"6mm X M5 6mm X M66mm X 1/8" 6mm X 1/4"6mm X 3/8" 6mm X 1/2"8mm X 1/8" 8mm X 1/4"8mm X 3/8" 8mm X 1/2"10mm X 1/8" 10mm X 1/4"10mm X 3/8" 10mm X 1/2"12mm X 1/8" 12mm X 1/4"12mm X 3/8" 12mm X 1/2"16mm X 1/8" 16mm X 1/4"16mm X 3/8" 16mm X 1/2"Other sizes are also available.Available Thread Type:BSP,NPT,UNF,GMaterial:Nickel plated brass and P