The cantilevered, or similar, design is critical to provide the design which allows for {TAIL ~ the separation} between the cathode and {HEAD ~ the insulator ring} 
The cantilevered , or similar , design is critical to provide the design which allows for { TAIL ~ the separation } between the cathode and { HEAD ~ the insulator ring }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD