diff --git a/Cargo.lock b/Cargo.lock
index e21fb3c..47df7de 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -33,7 +33,7 @@ dependencies = [
 
 [[package]]
 name = "graph_force"
-version = "0.1.2"
+version = "0.1.3"
 dependencies = [
  "pyo3",
  "rand",
diff --git a/Cargo.toml b/Cargo.toml
index 85e1d0c..a0515e9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "graph_force"
-version = "0.1.2"
+version = "0.1.3"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
diff --git a/src/lib.rs b/src/lib.rs
index 9ae3ad4..397d8e0 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,22 +1,37 @@
 mod graph;
 mod model;
+mod networkx_model;
 mod runner;
 mod spring_model;
 mod utils;
 
-use std::sync::{Arc, RwLock};
-
 use pyo3::exceptions;
 use pyo3::{prelude::*, types::PyIterator};
 
-#[pyfunction(number_of_nodes, edges, "*", iter = 500, threads = 0)]
+#[pyfunction(
+    number_of_nodes,
+    edges,
+    "*",
+    iter = 500,
+    threads = 0,
+    model = "\"spring_model\""
+)]
 fn layout_from_edge_list(
     number_of_nodes: usize,
     edges: &PyAny,
     iter: usize,
     threads: usize,
+    model: &str,
 ) -> PyResult<Vec<(f32, f32)>> {
-    let model = Arc::new(RwLock::new(spring_model::SimpleSpringModel::new(1.0)));
+    let model: Box<dyn model::ForceModel + Send + Sync> = match model {
+        "spring_model" => Box::new(spring_model::SimpleSpringModel::new(1.0)),
+        "networkx_model" => Box::new(networkx_model::NetworkXModel::new()),
+        _ => {
+            return Err(PyErr::new::<exceptions::PyValueError, _>(
+                "model must be either 'spring_model' or 'networkx_model'",
+            ))
+        }
+    };
 
     let mut edge_matrix = graph::new_edge_matrix(number_of_nodes);
     match edges.extract::<&PyIterator>() {
diff --git a/src/runner.rs b/src/runner.rs
index 9f6959f..c7652c4 100644
--- a/src/runner.rs
+++ b/src/runner.rs
@@ -30,16 +30,18 @@ impl Runner {
         }
     }
 
-    pub fn layout<T: 'static + ForceModel + Sync + Send>(
+    pub fn layout(
         self: &Self,
         number_of_nodes: usize,
         edges: EdgeMatrix,
-        model: Arc<RwLock<T>>,
+        model: Box<dyn ForceModel + Send + Sync>,
     ) -> Vec<(f32, f32)> {
         // let edges = connection_matrix(size);
         let mut nodes = new_node_vector(number_of_nodes);
         let mut nodes_next = new_node_vector(number_of_nodes);
 
+        let model = Arc::new(RwLock::new(model));
+
         model
             .write()
             .unwrap()
@@ -109,7 +111,7 @@ mod test {
 
     #[test]
     fn test_layout() {
-        let model = Arc::new(RwLock::new(MockModel { counter: 0 }));
+        let model = Box::new(MockModel { counter: 0 });
         let runner = Runner::new(10, 1);
         let edges = graph::new_edge_matrix(3);
         let result = runner.layout(3, edges, model);
diff --git a/tests/test_e2e.py b/tests/test_e2e.py
index a9e71b6..e3eba9c 100644
--- a/tests/test_e2e.py
+++ b/tests/test_e2e.py
@@ -22,3 +22,9 @@ def test_tuple_of_edges():
     )
     assert pos is not None
     assert len(pos) == 7
+
+def test_model_selection():
+    edges = [(1, 2), (2, 3), (3, 4), (4, 5), (5, 6)]
+    pos = graph_force.layout_from_edge_list(7, edges, model='networkx_model')
+    assert pos is not None
+    assert len(pos) == 7