diff --git a/oephys2nix/tonix.py b/oephys2nix/tonix.py
index e4dbce8..9767a8e 100644
--- a/oephys2nix/tonix.py
+++ b/oephys2nix/tonix.py
@@ -14,6 +14,36 @@ log = logging.getLogger(__name__)
 
 
 class RawToNix:
+    """Appending all raw data from relacs and open-ephsy to a new nix file.
+
+    Parameters
+    ----------
+    open_ephys_path: pathlib.Path
+        Path to open-ephys recording
+    relacs_nix_path : str
+        Path to relacs nix file
+    nix_file : str
+        Path to new nix file
+
+    Attributes
+    ----------
+    relacs_nix_file : nixio.File
+        Relacs nix file
+    dataset : rlx.Dataset
+        Dataset of the relacs file
+    relacs_block : nixio.Block
+        Relacs block
+    relacs_sections : nixio.Section
+        Relacs section
+    neo_data : neo.OpenEphysBinaryIO
+        Open Ephys data
+    nix_file : nixio.File
+        New nix file
+    block : nixio.Block
+        New nix file block
+
+    """
+
     def __init__(self, open_ephys_path: pathlib.Path, relacs_nix_path: str, nix_file: str):
         self.relacs_nix_file = nixio.File.open(relacs_nix_path, nixio.FileMode.ReadOnly)
         self.dataset = rlx.Dataset(relacs_nix_path)
@@ -25,7 +55,8 @@ class RawToNix:
         self.nix_file.create_block("open-ephys.data", "open-ephys.sampled")
         self.block = self.nix_file.blocks[0]
 
-    def append_section(self):
+    def append_section(self) -> None:
+        """Append sections from relacs."""
         sec = self.nix_file.create_section(
             self.relacs_sections[0].name, self.relacs_sections[0].type
         )
@@ -33,7 +64,8 @@ class RawToNix:
         create_metadata_from_dict(d, sec)
         self.block.metadata = sec
 
-    def append_fish_lines(self):
+    def append_fish_lines(self) -> None:
+        """Append fish lines from open-ephys."""
         efishs = ["ttl-line", "global-eod", "stimulus", "local-eod", "sinus"]
 
         efish_types = [
@@ -63,7 +95,8 @@ class RawToNix:
             )
             efish_group.data_arrays.append(data_array)
 
-    def append_relacs_lines(self):
+    def append_relacs_lines(self) -> None:
+        """Append relacs lines."""
         relacs = [
             "V-1",
             "EOD",
@@ -111,7 +144,8 @@ class RawToNix:
 
             efish_group.data_arrays.append(data_array)
 
-    def append_raw_data(self):
+    def append_raw_data(self) -> None:
+        """Append Open-Ephys Raw data."""
         gr = self.block.create_group("neuronal-data", "open-epyhs.sampled")
         raw_neo_data = self.neo_data[0].segments[0].analogsignals[0].load()
 
@@ -128,6 +162,7 @@ class RawToNix:
         )
         gr.data_arrays.append(nix_data_array)
 
-    def close(self):
+    def close(self) -> None:
+        """Close all nix files."""
         self.nix_file.close()
         self.relacs_nix_file.close()