{HEAD ~ The chopper module} 1, wherein {TAIL ~ the plurality} of longitudinal channels comprises four longitudinal channels 
wherein
{ HEAD ~ The chopper module } 1 , wherein { TAIL ~ the plurality } of longitudinal channels comprises four longitudinal channels
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH