diff --git a/src/kcorrect/fitter.py b/src/kcorrect/fitter.py
index 0f0c0a8..f939300 100644
--- a/src/kcorrect/fitter.py
+++ b/src/kcorrect/fitter.py
@@ -141,8 +141,7 @@ def set_Amatrix(self):
 
         return
 
-    def _fit_coeffs(self, redshift=None, maggies=None, ivar=None,
-                    mc=0):
+    def _fit_coeffs(self, redshift=None, maggies=None, ivar=None, mc=0):
         """Fit coefficients to single object
 
         Parameters
diff --git a/src/kcorrect/kcorrect.py b/src/kcorrect/kcorrect.py
index 6e5fcfe..ae21d32 100644
--- a/src/kcorrect/kcorrect.py
+++ b/src/kcorrect/kcorrect.py
@@ -26,6 +26,9 @@ class Kcorrect(kcorrect.fitter.Fitter):
     abcorrect : bool
         correct maggies to AB (default False)
 
+    filename : str
+        input file to define kcorrect object (overrides responses, responses_out, responses_map, templates, redshift_range, nredshift, abcorrect)
+
     responses : list of str
         names of input responses to base SED on
 
@@ -115,6 +118,10 @@ class Kcorrect(kcorrect.fitter.Fitter):
 
     AmatrixOut is similar but returns a [nresponses_out, ntemplates]
     matrix for the output bandpasses.
+
+    Once defined, a Kcorrect object can be output to a FITS file with 
+    the method tofits(), and reimported with fromfits(). The filename
+    parameter expects this format.
 """
     def __init__(self, filename=None, responses=None, templates=None,
                  responses_out=None, responses_map=None,
@@ -215,6 +222,9 @@ def derived(self, redshift=None, coeffs=None, band_shift=0., distance=None):
         'mtol' : ndarray of np.float32, or np.float32
              [ngalaxy] mass-to-light ratio in each output band
 
+        'b50' : ndarray of np.float32, or np.float32
+             [ngalaxy] current (< 50 Myr) over past star formation
+
         'b300' : ndarray of np.float32, or np.float32
              [ngalaxy] current (< 300 Myr) over past star formation
 
@@ -349,6 +359,9 @@ def derived_mc(self, redshift=None, coeffs_mc=None, band_shift=0., distance=None
         'mtol' : ndarray of np.float32, or np.float32
              [ngalaxy, mc] mass-to-light ratio in each output band
 
+        'b50' : ndarray of np.float32, or np.float32
+             [ngalaxy] current (< 50 Myr) over past star formation
+
         'b300' : ndarray of np.float32, or np.float32
              [ngalaxy, mc] current (< 300 Myr) over past star formation
 
@@ -450,7 +463,7 @@ def kcorrect(self, redshift=None, coeffs=None, band_shift=0.):
         return(kcorrect)
 
     def absmag(self, maggies=None, ivar=None, redshift=None, coeffs=None,
-               band_shift=0., distance=None, coeffs_mc=None):
+               band_shift=0., distance=None):
         """Return absolute magnitude in output bands
 
         Parameters
diff --git a/src/kcorrect/response.py b/src/kcorrect/response.py
index 3ef5ed7..5b8cba4 100644
--- a/src/kcorrect/response.py
+++ b/src/kcorrect/response.py
@@ -134,6 +134,9 @@ class Response(object):
     filename : str
         source filename, or None
 
+    fwhm, fwhm_low, fwhm_hight : np.float32
+        FWHM of response, with low and high wavelength limits (Angstroms)
+
     interp : scipy.interpolate.interp1d object
         interpolation object
 
diff --git a/src/kcorrect/template.py b/src/kcorrect/template.py
index ddde8d3..84dc833 100644
--- a/src/kcorrect/template.py
+++ b/src/kcorrect/template.py
@@ -26,6 +26,9 @@ class SED(object):
     flux : ndarray of np.float32
         [nsed, nwave] rest frame flux grid in erg/cm^2/s/A at 10pc
 
+    ext : str
+        extension from which to read FLUX in FITS file
+
     Attributes
     ----------
 
@@ -285,6 +288,9 @@ class Template(SED):
     binimage : bool
         if True, read in WAVE and FLUX extensions as binary images
 
+    ext : str
+        extension from which to read FLUX in FITS file
+
     Attributes
     ----------