diff --git a/sadie/__init__.py b/sadie/__init__.py
index 1dae9da..eac90e7 100644
--- a/sadie/__init__.py
+++ b/sadie/__init__.py
@@ -2,7 +2,7 @@
 
 __author__ = """Chris von Csefalvay"""
 __email__ = 'chris@chrisvoncsefalvay.com'
-__version__ = '0.1.9'
+__version__ = '0.2.0'
 
 from sadie.models.base import *  # noqa
 from sadie.models.simple import *  # noqa
diff --git a/sadie/agents/walkers.py b/sadie/agents/walkers.py
index af5925d..89b2bbd 100644
--- a/sadie/agents/walkers.py
+++ b/sadie/agents/walkers.py
@@ -150,6 +150,13 @@ def update(self):
 
 
 class VariableVelocityWalker(BaseWalker):
+    """
+    Variable velocity walkers have a velocity distributed based on a probability distribution, `velocity_distribution`.
+    In general, velocities cannot be negative. There are two behaviours, conditioned by the `reflect` parameter:
+
+    * reflection (`reflect = True`): if the random value from the distribution is negative, the absolute value is taken,
+    * capping (`reflect = True`): if the random value from the distribution is negative, 0 is used.
+    """
     def __init__(self,
                  x_init: float,
                  y_init: float,
diff --git a/setup.cfg b/setup.cfg
index 4ba3b76..449140b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,5 +1,5 @@
 [bumpversion]
-current_version = 0.1.9
+current_version = 0.2.0
 commit = True
 tag = True
 
diff --git a/setup.py b/setup.py
index fd23030..01b0eb7 100644
--- a/setup.py
+++ b/setup.py
@@ -43,6 +43,6 @@
     test_suite='tests',
     tests_require=test_requirements,
     url='https://github.com/chrisvoncsefalvay/sadie',
-    version='0.1.9',
+    version='0.2.0',
     zip_safe=False,
 )