diff --git a/src/histolab/tiler.py b/src/histolab/tiler.py
index c8d952f43..29bf491dc 100644
--- a/src/histolab/tiler.py
+++ b/src/histolab/tiler.py
@@ -29,9 +29,9 @@ class Tiler(Protocol):
 
     @lru_cache(maxsize=100)
     def box_mask_thumb(self, slide: Slide) -> np.ndarray:
-        """Return binary mask at thumbnail dimensions of the box for tiles extraction.
+        """Return binary mask, at thumbnail level, of the box for tiles extraction.
 
-        The mask pixels set to True will be the ones corresponding to the tissue box.
+        The mask pixels set to True correspond to the tissue box.
 
         Parameters
         ----------
@@ -41,7 +41,7 @@ def box_mask_thumb(self, slide: Slide) -> np.ndarray:
         Returns
         -------
         np.ndarray
-            Extraction mask at thumbnail dimensions
+            Extraction mask at thumbnail level
         """
 
         return slide.biggest_tissue_box_mask