diff --git a/mocksipipeline/instrument/configuration/moxsi_short.py b/mocksipipeline/instrument/configuration/moxsi_short.py
index aafc89e..0cbf713 100644
--- a/mocksipipeline/instrument/configuration/moxsi_short.py
+++ b/mocksipipeline/instrument/configuration/moxsi_short.py
@@ -8,7 +8,8 @@
 from mocksipipeline.instrument.optics.aperture import CircularAperture
 from mocksipipeline.instrument.optics.configuration import short_design
 from mocksipipeline.instrument.optics.filter import ThinFilmFilter
-from mocksipipeline.instrument.optics.response import Channel
+from mocksipipeline.instrument.optics.response import (ALLOWED_SPECTRAL_ORDERS,
+                                                       Channel)
 
 __all__ = [
     'moxsi_short',
@@ -74,12 +75,11 @@
                        aperture=pinhole)
 
 # Set up spectrograms
-orders = [-4, -3, -2, -1, 0, 1, 2, 3, 4]
 spectrogram_1_refpix = ((short_design.detector_shape[1] - 1) / 2,
                         (short_design.detector_shape[0] / 2 - 1) / 2,
                         0) * u.pix
 spectrograms = []
-for order in orders:
+for order in ALLOWED_SPECTRAL_ORDERS:
     chan = Channel(name='spectrogram_1',
                    order=order,
                    filters=[al_thin, al_oxide],
diff --git a/mocksipipeline/instrument/configuration/moxsi_slot.py b/mocksipipeline/instrument/configuration/moxsi_slot.py
index 3c18f4d..93c7929 100644
--- a/mocksipipeline/instrument/configuration/moxsi_slot.py
+++ b/mocksipipeline/instrument/configuration/moxsi_slot.py
@@ -9,7 +9,8 @@
                                                        SlotAperture)
 from mocksipipeline.instrument.optics.configuration import short_design
 from mocksipipeline.instrument.optics.filter import ThinFilmFilter
-from mocksipipeline.instrument.optics.response import Channel
+from mocksipipeline.instrument.optics.response import (ALLOWED_SPECTRAL_ORDERS,
+                                                       Channel)
 
 __all__ = [
     'moxsi_slot',
@@ -83,10 +84,9 @@
                        aperture=pinhole)
 
 # Set up spectrograms
-orders = [-4, -3, -2, -1, 0, 1, 2, 3, 4]
 spectrograms_pinhole = []
 spectrograms_slot = []
-for order in orders:
+for order in ALLOWED_SPECTRAL_ORDERS:
     spectrograms_pinhole.append(
         Channel(name='spectrogram_pinhole',
                 order=order,
diff --git a/mocksipipeline/instrument/optics/response.py b/mocksipipeline/instrument/optics/response.py
index e8d5a52..02c7fcc 100644
--- a/mocksipipeline/instrument/optics/response.py
+++ b/mocksipipeline/instrument/optics/response.py
@@ -15,6 +15,22 @@
 
 from mocksipipeline.instrument.optics.filter import ThinFilmFilter
 
+ALLOWED_SPECTRAL_ORDERS = [
+    -6,
+    -5,
+    -4,
+    -3,
+    -2,
+    -1,
+    0,
+    1,
+    2,
+    3,
+    4,
+    5,
+    6,
+]
+
 __all__ = [
     'Channel',
 ]
@@ -96,8 +112,7 @@ def spectral_order(self):
 
     @spectral_order.setter
     def spectral_order(self, value):
-        allowed_spectral_orders = [-4, -3, -2, -1, 0, 1, 2, 3, 4]
-        if value not in allowed_spectral_orders:
+        if value not in ALLOWED_SPECTRAL_ORDERS:
             raise ValueError(f'{value} is not an allowed spectral order.')
         self._spectral_order = value