{HEAD ~ The motor} is powered by a power supply, e.g., a battery pack, located within {TAIL ~ the housing} 
{ HEAD ~ The motor } is powered by a power supply , e.g. , a battery pack , located within { TAIL ~ the housing }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL