{TAIL ~ A filter} of the type depicted in FIG 2 is suitable for infrared radiation in the spectral range of wavelengths from approximately 1.8 microns to {HEAD ~ 1000 microns} 
{ TAIL ~ A filter } of the type depicted in FIG 2 is suitable for infrared radiation in the spectral range of wavelengths from approximately 1.8 microns to { HEAD ~ 1000 microns }
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD