The selection and manufacture of such apparatus is within the ordinary skill in the art and can be done using {HEAD ~ components} which are easily constructed or obtained from {TAIL ~ commercial suppliers} 
are easily obtained from
The selection and manufacture of such apparatus is within the ordinary skill in the art and can be done using { HEAD ~ components } which are easily constructed or obtained from { TAIL ~ commercial suppliers }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH REL REL OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL