Preferably, {HEAD ~ the contact spring part} is {TAIL ~ approximately the length} of the rear section of the guide pin to optimize the mechanical connection 
is
Preferably , { HEAD ~ the contact spring part } is { TAIL ~ approximately the length } of the rear section of the guide pin to optimize the mechanical connection
OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH