Breathing System Filter Y4/D17 Standard: YZB 0262-2003,YY 0321.3 Usage: ... : to tank 5um insoluble particles should be greater than 90% filter rate3.30N static pressure, flow rate, 20ml than 30S /4 ... .heavy metals, inspection of barium, chromium, copper, lead and tin content of total does not exceed 1ug/ml.Min order:500pieces ...