The light sources may be {TAIL ~ light emitting diodes} or {HEAD ~ other standard light sources} that can be contained in the handle of the delivery tool 
The light sources may be { TAIL ~ light emitting diodes } or { HEAD ~ other standard light sources } that can be contained in the handle of the delivery tool
OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH