diff --git a/mtenn/conversion_utils/e3nn.py b/mtenn/conversion_utils/e3nn.py
index 214ab12..9bf26f8 100644
--- a/mtenn/conversion_utils/e3nn.py
+++ b/mtenn/conversion_utils/e3nn.py
@@ -108,6 +108,7 @@ def _get_representation(self, reduce_output=False):
         # Remove last layer
         model_copy.layers = model_copy.layers[:-1]
         model_copy.reduce_output = reduce_output
+        model_copy.irreps_out = model_copy.layers[-1].irreps_out
 
         return model_copy
 
@@ -169,7 +170,10 @@ def _get_concat_strategy(self):
             ``ConcatStrategy`` for the model
         """
 
-        return ConcatStrategy(extract_key="x")
+        # Calculate input size as 3 * dimensionality of output of Representation
+        #  (last layer in Representation is 2nd to last in original model)
+        input_size = 3 * self.layers[-2].irreps_out.dim
+        return ConcatStrategy(input_size=input_size, extract_key="x")
 
     @staticmethod
     def get_model(
@@ -227,24 +231,21 @@ def get_model(
         if model is None:
             model = E3NN(model_kwargs)
 
+        # Get representation module
+        representation = model._get_representation(reduce_output=strategy == "concat")
+
         # Construct strategy module based on model and
         #  representation (if necessary)
         strategy = strategy.lower()
         if strategy == "delta":
             strategy = model._get_delta_strategy()
-            reduce_output = False
         elif strategy == "concat":
             strategy = model._get_concat_strategy()
-            reduce_output = True
         elif strategy == "complex":
             strategy = model._get_complex_only_strategy()
-            reduce_output = False
         else:
             raise ValueError(f"Unknown strategy: {strategy}")
 
-        # Get representation module
-        representation = model._get_representation(reduce_output=reduce_output)
-
         # Check on `combination`
         if grouped and (combination is None):
             raise ValueError(
diff --git a/mtenn/conversion_utils/schnet.py b/mtenn/conversion_utils/schnet.py
index b92944c..a26db02 100644
--- a/mtenn/conversion_utils/schnet.py
+++ b/mtenn/conversion_utils/schnet.py
@@ -143,6 +143,22 @@ def _get_complex_only_strategy(self):
 
         return ComplexOnlyStrategy(self._get_energy_func())
 
+    def _get_concat_strategy(self):
+        """
+        Build a :py:class:`ConcatStrategy <mtenn.strategy.ConcatStrategy>` object with
+        the appropriate ``input_size``.
+
+        Returns
+        -------
+        ConcatStrategy
+            ``ConcatStrategy`` for the model
+        """
+
+        # Calculate input size as 3 * dimensionality of output of Representation
+        #  (ie lin1 layer)
+        input_size = 3 * self.lin1.out_features
+        return ConcatStrategy(input_size=input_size)
+
     @staticmethod
     def get_model(
         model=None,
@@ -203,7 +219,7 @@ def get_model(
         if strategy == "delta":
             strategy = model._get_delta_strategy()
         elif strategy == "concat":
-            strategy = ConcatStrategy()
+            strategy = model._get_concat_strategy()
         elif strategy == "complex":
             strategy = model._get_complex_only_strategy()
         else:
diff --git a/mtenn/strategy.py b/mtenn/strategy.py
index 4def3ef..5a4d89c 100644
--- a/mtenn/strategy.py
+++ b/mtenn/strategy.py
@@ -115,18 +115,20 @@ class ConcatStrategy(Strategy):
     initialize a one-layer linear network of the appropriate dimensionality.
     """
 
-    def __init__(self, extract_key=None):
+    def __init__(self, input_size, extract_key=None):
         """
         Set the key to use to access vector representations if ``dict`` s are passed to
         the ``forward`` call.
 
         Parameters
         ----------
+        input_size : int
+            Input size of linear model
         extract_key : str, optional
             Key to use to extract representation from a dict
         """
         super(ConcatStrategy, self).__init__()
-        self.reduce_nn: torch.nn.Module = None
+        self.reduce_nn = torch.nn.Linear(input_size, 1)
         self.extract_key = extract_key
 
     def forward(self, comp, *parts):
@@ -158,17 +160,8 @@ def forward(self, comp, *parts):
         comp = comp.flatten()
         parts = [p.flatten() for p in parts]
 
-        parts_size = sum([len(p) for p in parts])
-        if self.reduce_nn is None:
-            # If we haven't already, initialize a Linear module with appropriate input
-            #  size
-            input_size = len(comp) + parts_size
-            self.reduce_nn = torch.nn.Linear(input_size, 1)
-
-        # Move self.reduce_nn to appropriate torch device
-        self.reduce_nn = self.reduce_nn.to(comp.device)
-
         # Enumerate all possible permutations of parts and add together
+        parts_size = sum([len(p) for p in parts])
         parts_cat = torch.zeros((parts_size), device=comp.device)
         for idxs in permutations(range(len(parts)), len(parts)):
             parts_cat += torch.cat([parts[i] for i in idxs])