Used for sampling air volumes at low jet velocity. Bottle joint is 24/40. Stopper uses #7 Ace-Safe removable hose connections for easy connect/disconnect. Impinge nozzle calibrated to deliver 0.09 to 0.11 CFM at 30.5cm (12") H2O vacuum. Bubbler nozzle has sintered glass filter, porosity A (145-175 microns) or porosity B (70-100 microns). Bottle has encircling graduations from 0 to 25mL or 0 to 30mL in 5mL divisions. Complete item supplied with connectors and bushings.