The barrier is furthermore spaced radially away from the central portion or {TAIL ~ stem} of the insulator over at least a substantial part of the inner periphery of {HEAD ~ the barrier} 
The barrier is furthermore spaced radially away from the central portion or { TAIL ~ stem } of the insulator over at least a substantial part of the inner periphery of { HEAD ~ the barrier }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD