diff --git a/CHANGELOG.md b/CHANGELOG.md
index 29f1f0a..147c6c7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,16 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 
+## [v0.1.3] - 2019-05-04
+
+### Added
+- Items.search_geometry() function added to return search geometry
+- Extension of `Item` files can now be specified in `Item.get_filename()`. Defaults to `item.json`.
+- Specify STAC version by setting SATUTILS_STAC_VERSION environment variable. Currently defaults to '0.6.2'.
+
+### Changed
+- Items objects no longer require a Collection for every Item
+
 ## [v0.1.2] - 2019-02-14
 
 ### Added
@@ -30,6 +40,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 Initial Release
 
 [Unreleased]: https://github.com/sat-utils/sat-stac/compare/master...develop
+[v0.1.3]: https://github.com/sat-utils/sat-stac/compare/0.1.2...v0.1.3
 [v0.1.2]: https://github.com/sat-utils/sat-stac/compare/0.1.1...v0.1.2
 [v0.1.1]: https://github.com/sat-utils/sat-stac/compare/0.1.0...v0.1.1
 [v0.1.0]: https://github.com/sat-utils/sat-stac/tree/0.1.0
diff --git a/README.md b/README.md
index 1a899e6..2da4ccb 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@ $ pip install .
 
 
 #### Versions
-The latest version of sat-stac is 0.1.1, which uses the STAC spec v0.6.0. To install other versions of sat-stac, install the matching version of sat-stac. 
+To install a specific versions of sat-stac, install the matching version of sat-stac. 
 
 ```bash
 pip install sat-stac==0.1.0
@@ -40,7 +40,7 @@ The table below shows the corresponding versions between sat-stac and STAC:
 
 | sat-stac | STAC  |
 | -------- | ----  |
-| 0.1.x    | 0.6.0 |
+| 0.1.x    | 0.6.x |
 
 ## Tutorials
 
diff --git a/satstac/catalog.py b/satstac/catalog.py
index b9fd6b2..011c474 100644
--- a/satstac/catalog.py
+++ b/satstac/catalog.py
@@ -3,9 +3,7 @@
 
 from .version import __version__
 from .thing import Thing, STACError
-
-
-STAC_VERSION='0.6.0'
+from .config import STAC_VERSION
 
 
 class Catalog(Thing):
diff --git a/satstac/config.py b/satstac/config.py
new file mode 100644
index 0000000..8bac768
--- /dev/null
+++ b/satstac/config.py
@@ -0,0 +1,4 @@
+import os
+
+STAC_VERSION = os.getenv('SATUTILS_STAC_VERSION', '0.6.2')
+
diff --git a/satstac/item.py b/satstac/item.py
index 672d806..96753dd 100644
--- a/satstac/item.py
+++ b/satstac/item.py
@@ -102,11 +102,11 @@ def asset(self, key):
         logging.warning('No such asset (%s)' % key)
         return None
 
-    def get_filename(self, path='', filename='${id}'):
+    def get_filename(self, path='', filename='${id}', extension='.json'):
         """ Get complete path with filename to this item """
         return os.path.join(
             self.substitute(path),
-            self.substitute(filename) + '.json'
+            self.substitute(filename) + extension
         )
 
     def substitute(self, string):
diff --git a/satstac/items.py b/satstac/items.py
index 79e60ad..b0d4c1e 100644
--- a/satstac/items.py
+++ b/satstac/items.py
@@ -16,7 +16,9 @@ def __init__(self, items, collections=[], search={}):
         # link Items to their Collections
         cols = {c.id: c for c in self._collections}
         for i in self._items:
-            i._collection = cols[i['collection']]
+            if 'collection' in i.properties:
+                if i['collection'] in cols:
+                    i._collection = cols[i['collection']]
 
     @classmethod
     def load(cls, filename):
@@ -65,6 +67,12 @@ def center(self):
         else:
             return None
 
+    def search_geometry(self):
+        if 'intersects' in self._search:
+            return self._search['intersects']
+        else:
+            return None
+
     def properties(self, key, date=None):
         """ Set of values for 'key' property in Items, for specific date if provided """
         if date is None:
diff --git a/satstac/version.py b/satstac/version.py
index 10939f0..8ce9b36 100644
--- a/satstac/version.py
+++ b/satstac/version.py
@@ -1 +1 @@
-__version__ = '0.1.2'
+__version__ = '0.1.3'