The integrated power unit may perform either function, and {HEAD ~ transition} between {TAIL ~ functions}, while affording a smaller and lighter apparatus than the total of the two units which it replaces 
between
The integrated power unit may perform either function , and { HEAD ~ transition } between { TAIL ~ functions } , while affording a smaller and lighter apparatus than the total of the two units which it replaces
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH