I recently ordered a tank, fill valve and din fittings from China. I got the Acecare 2.17L tank which is very nice looking and the fill valve. The fill valve had some o-rings and other parts that I think I know how they assemble. But the way the pressure gauge turns as you open the valve seems strange to me and the red knob is loose. There are two set screws on either side of the red knob but either tighten or loosen the knob still seems loose. Hope I did not get burned on this valve purchase. The tank takes an M18x1.5 thread. Bill