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