Midget Impinger, Graduated, Complete, 24/40 Joint Size, 12/5 Tip. Micro impinger designed for sampling of small volumes of air at low jet velocity, as per EPA Method 6. Impinger bottle is graduated from 5 to 30ml in 5ml subdivisions. Both the bottle and stopper have 24/40 standard taper joints. The orifice at the impinger tip is 1mm, passing 0.09 to 0.11 CFM of air at 12in H20 vacuum. Equipped with 12/5 ball joints.