For {HEAD ~ a given source pressure}, {TAIL ~ the loose fill insulation} has a characteristic pressure drop for a given density 
For { HEAD ~ a given source pressure } , { TAIL ~ the loose fill insulation } has a characteristic pressure drop for a given density
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH