diff --git a/python/_cosmotool.pyx b/python/_cosmotool.pyx
index 0f71252..2d20a35 100644
--- a/python/_cosmotool.pyx
+++ b/python/_cosmotool.pyx
@@ -184,10 +184,10 @@ class _PySimulationAdaptor(PySimulationBase):
 
 cdef class ArrayWrapper:
     cdef void* data_ptr
-    cdef int size
+    cdef np.uint64_t size
     cdef int type_array
     
-    cdef set_data(self, int size, int type_array, void* data_ptr):
+    cdef set_data(self, np.uint64_t size, int type_array, void* data_ptr):
         """ Set the data of the array
 
 This cannot be done in the constructor as it must recieve C-level
@@ -302,6 +302,19 @@ It loads a gadget-1 snapshot and return a PySimulationBase object. If cpu_id is
   return _PySimulationAdaptor(wrap_simudata(data, flags))
 
 def loadParallelGadget(object filename_list, bool loadPosition = True, bool loadVelocity = False, bool loadId = False, bool loadType = False, bool loadMass=False):
+  """loadGadget(filename list, loadPosition=True, loadVelocity=False, loadId=False, loadType=False)
+
+  Arguments:
+    - filename list: a list or tuple of filenames to load in parallel
+  
+  Keywords:
+    - loadPosition: indicate to load positions
+    - loadVelocity: indicate to load velocities
+    - loadId: indicate to load id
+    - loadType: indicate to load particle types
+    
+It loads a gadget-1 snapshot and return a PySimulationBase object.
+"""
   cdef int flags, i, num_files
   cdef list out_arrays
   cdef SimuData ** data