A windup/unwind mechanism can be connected to {TAIL ~ the roll} and is capable of locking in selected positions for selecting {HEAD ~ the tension} of the barrier member 
A windup / unwind mechanism can be connected to { TAIL ~ the roll } and is capable of locking in selected positions for selecting { HEAD ~ the tension } of the barrier member
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH