A high velocity impinger air sampling which passes 6L/min (corrected to engineering gas conditions) when the pressure drop across the orifice is 41cm Hg or greater. Stopper fits 24/25 125ml bottle and features a 11mm OD center tube, 8mm OD side arm with bulge, 0.035in capillary tip that is positioned 4mm above the bottom of the bottle. Particulate capture range: 0.6 to 2 microns.