... 1.all types 2.good quality,good price 3.have own factory,large quantity 4 ... series of Asia, southeast Asia, Japan, South Korea, China, etc. To the metric system for standard size, with ... is generally g6. Two big series structure characteristics, in addition to different sizes, aperture tolerance is different, ... 3: open the mouth (shapes such as straight tube, appearance had axial cut seam, used for gap ...