diff --git a/kibot/gs.py b/kibot/gs.py
index 42a0e5dc..0c4b7063 100644
--- a/kibot/gs.py
+++ b/kibot/gs.py
@@ -89,6 +89,9 @@ class GS(object):
     stackup = None
     # Preprocessor definitions
     cli_defines = {}
+    kikit_units_to_kicad = {'mm': pcbnew.IU_PER_MM, 'cm': 10*pcbnew.IU_PER_MM, 'dm': 100*pcbnew.IU_PER_MM,
+                            'm': 1000*pcbnew.IU_PER_MM, 'mil': pcbnew.IU_PER_MILS, 'inch': 1000*pcbnew.IU_PER_MILS,
+                            'in': 1000*pcbnew.IU_PER_MILS}
     #
     # Global defaults
     #
@@ -447,3 +450,7 @@ class GS(object):
             return dir_name
         logger.error('Missing resource directory `{}`'.format(name))
         exit(WRONG_INSTALL)
+
+    @staticmethod
+    def create_eda_rect(tlx, tly, brx, bry):
+        return pcbnew.EDA_RECT(pcbnew.wxPoint(tlx, tly), pcbnew.wxSize(brx-tlx, bry-tly))
diff --git a/kibot/optionable.py b/kibot/optionable.py
index 7f88294b..c66309d7 100644
--- a/kibot/optionable.py
+++ b/kibot/optionable.py
@@ -535,15 +535,20 @@ class PanelOptions(BaseOptions):
     _num_regex = re.compile(r'([\d\.]+)(mm|cm|dm|m|mil|inch|in)')
     _ang_regex = re.compile(r'([\d\.]+)(deg|°|rad)')
 
-    def add_units(self, ops, def_units=None):
+    def add_units(self, ops, def_units=None, convert=False):
         if def_units is None:
             def_units = self._parent._parent.units
         for op in ops:
             val = getattr(self, op)
+            _op = '_'+op
             if val is None:
+                if convert:
+                    setattr(self, _op, 0)
                 continue
             if isinstance(val, (int, float)):
                 setattr(self, op, str(val)+def_units)
+                if convert:
+                    setattr(self, _op, val*GS.kikit_units_to_kicad[def_units])
             else:
                 m = PanelOptions._num_regex.match(val)
                 if m is None:
@@ -555,6 +560,8 @@ class PanelOptions(BaseOptions):
                     num_d = None
                 if num_d is None:
                     raise KiPlotConfigurationError('Malformed number in `{}` ({})'.format(op, num))
+                if convert:
+                    setattr(self, _op, num_d*GS.kikit_units_to_kicad[m.group(2)])
 
     def add_angle(self, ops, def_units=None):
         if def_units is None:
diff --git a/kibot/var_base.py b/kibot/var_base.py
index c4714533..31650c18 100644
--- a/kibot/var_base.py
+++ b/kibot/var_base.py
@@ -64,7 +64,8 @@ class SubPCBOptions(PanelOptions):
         if (not self.reference and self.is_zero(self.tlx) and self.is_zero(self.tly) and self.is_zero(self.brx) and
            self.is_zero(self.bry)):
             raise KiPlotConfigurationError('No reference or rectangle specified for {} sub-PCB'.format(self.name))
-        self.add_units(('tlx', 'tly', 'brx', 'bry'), self.units)
+        self.add_units(('tlx', 'tly', 'brx', 'bry'), self.units, convert=True)
+        self.board_rect = GS.create_eda_rect(self._tlx, self._tly, self._brx, self._bry)
 
     def get_separate_source(self):
         if self.reference:
@@ -86,7 +87,6 @@ class SubPCBOptions(PanelOptions):
             run_command(cmd)
             # Load this board
             GS.load_board(dest, forced=True)
-            self._excl_by_sub_pcb = set()
             # Now reflect the changes in the list of components
             if comps_hash:
                 logger.debug('Removing components outside the sub-PCB')
@@ -103,22 +103,65 @@ class SubPCBOptions(PanelOptions):
                         self._excl_by_sub_pcb.add(c)
                         logger.debugl(2, '- Removing '+c)
 
+    def _remove_items(self, iter):
+        """ Remove items outside the rectangle.
+            If the item has width (shapes and tracks) we discard it.
+            This produces something closer to KiKit. """
+        for m in iter:
+            with_width = hasattr(m, 'GetWidth')
+            if with_width:
+                width = m.GetWidth()
+                m.SetWidth(0)
+            if not self.board_rect.Contains(m.GetBoundingBox()):
+                GS.board.Remove(m)
+                self._removed.append(m)
+            if with_width:
+                m.SetWidth(width)
+
+    def _remove_modules(self, iter):
+        """ Remove modules outside the rectangle.
+            Footprints are added to the list of references to exclude.
+            We also check their position, not their BBox. """
+        for m in iter:
+            if not self.board_rect.Contains(m.GetPosition()):
+                GS.board.Remove(m)
+                self._removed.append(m)
+                self._excl_by_sub_pcb.add(m.GetReference())
+
+    def remove_outside(self):
+        self._removed = []
+        self._remove_modules(GS.get_modules())
+        self._remove_items(GS.board.GetDrawings())
+        self._remove_items(GS.board.GetTracks())
+        self._remove_items(list(GS.board.Zones()))
+
     def apply(self, comps_hash):
-        if True:
+        self._excl_by_sub_pcb = set()
+        if self.reference:
             self.separate_board(comps_hash)
+        else:
+            # Using a rectangle
+            self.remove_outside()
 
     def unload_board(self, comps_hash):
         # Undo the sub-PCB: just reload the PCB
         GS.load_board(forced=True)
+
+    def restore_removed(self):
+        """ Restore the stuff we removed from the board """
+        for o in self._removed:
+            GS.board.Add(o)
+
+    def revert(self, comps_hash):
+        if self.reference:
+            self.unload_board(comps_hash)
+        else:
+            self.restore_removed()
         # Restore excluded components
         logger.debug('Restoring components outside the sub-PCB')
         for c in self._excl_by_sub_pcb:
             comps_hash[c].included = True
 
-    def revert(self, comps_hash):
-        if True:
-            self.unload_board(comps_hash)
-
 
 class BaseVariant(RegVariant):
     def __init__(self):