PCO28mm preforms Long neck and short neck Good quality,100% new PET materials, ... ) High transparency. 3) High toughness 4) 28mm neck size, short neck or long neck5) Weight: short neck preform:23.5g -500ml,46g ... -4.5L or5L. There are many kinds of weight for long size preforms.6) Different colors (white, light blue, dark blue, transparent ...