The dust bag is angled relative to the wall and pressure sensors fill {HEAD ~ the space} between {TAIL ~ the wall} and dust bag 
between
The dust bag is angled relative to the wall and pressure sensors fill { HEAD ~ the space } between { TAIL ~ the wall } and dust bag
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH