The pad is made from {TAIL ~ a material} that is non reactive with {HEAD ~ the liquid control solution} 
The pad is made from { TAIL ~ a material } that is non reactive with { HEAD ~ the liquid control solution }
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD