The embodiment of the apparatus or method that uses the air cup relies on {TAIL ~ the natural resistance} to flow of the loose fill insulation to create {HEAD ~ a pressure drop} 
The embodiment of the apparatus or method that uses the air cup relies on { TAIL ~ the natural resistance } to flow of the loose fill insulation to create { HEAD ~ a pressure drop }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD