function gt_ssl_explab, item
;
;+
;NAME:
;	gt_ssl_explab
;PURPOSE:
;	Return the label for the SSL data structure fields
;	"num_expos" and "dur_expos"
;OPTIONAL INPUT:
;	item	- The indicy of the item wanted (0-12)
;		  If not specified, return them all.
;OUTPUT:
;	Returns a string array (or scalar) with the description
;	of what "num_expos" applies to
;HISTORY:
;	Written 24-Apr-92 by M.Morrison
;-
;
labels = strarr(13)
labels(0) = 'Al 1400 Angstrom                (Filter B = 2)
labels(1) = 'Al/Mg/Mn                        (Filter B = 3)
labels(2) = 'Ber 100 microns                 (Filter B = 4)
labels(3) = 'Al 12 microns                   (Filter B = 5)
labels(4) = 'Mg3Mu                           (Filter B = 6)
labels(5) = 'Narrow Band (4310 A, 30 A FWHM) (Filter A = 2)
labels(6) = 'Quartz defocusing lens          (Filter A = 3)
labels(7) = 'Diffuser                        (Filter A = 4)
labels(8) = 'Wide Band (4600 A, 185 A FWHM)  (Filter A = 5)
labels(9) = 'Neutral Density Mask (8%)       (Filter A = 6)
labels(10) = 'OPEN/OPEN
labels(11) = 'Dark images
labels(12) = 'Calibration (LTF) images
;
out = labels
if (n_elements(item) ne 0) then out = out(item)
;
return, out
end