diff --git a/Gruntfile.js b/Gruntfile.js
index 91470da..08c6270 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -188,7 +188,7 @@ grunt.initConfig({
 
     grid_units: {
         dest : 'build/grids-units.css',
-        units: 24
+        units: [5, 24]
     },
 
     // -- CSS Selectors Config -------------------------------------------------
diff --git a/package.json b/package.json
index df73a08..d38119d 100644
--- a/package.json
+++ b/package.json
@@ -9,6 +9,7 @@
   "devDependencies": {
     "bower": "~1.2.5",
     "grunt": "~0.4.1",
+    "grunt-cli": "~0.1.9",
     "grunt-contrib-cssmin": "~0.6.0",
     "grunt-contrib-clean": "~0.5.0",
     "grunt-contrib-copy": "~0.4.1",
@@ -17,6 +18,6 @@
     "grunt-contrib-csslint": "~0.1.2",
     "grunt-contrib-watch": "~0.5.3",
     "grunt-css-selectors": "~0.1.0",
-    "grunt-cli": "~0.1.9"
+    "rework-pure-grids": "0.0.2"
   }
 }
diff --git a/src/grids/README.md b/src/grids/README.md
new file mode 100644
index 0000000..04397bf
--- /dev/null
+++ b/src/grids/README.md
@@ -0,0 +1,13 @@
+Pure Grids
+==========
+
+Pure Grids ship with build-in 5ths- and 24ths-based units styles. The unit style
+rules are generated via Pure's [`rework-pure-grids`][rework-pure-grids]
+[Rework][] plugin.
+
+The tooling used by Pure to generate its built-in Grids can also be used to
+create custom Grids that use any nth-unit base.
+
+
+[rework-pure-grids]: https://github.com/ericf/rework-pure-grids
+[Rework]: https://github.com/visionmedia/rework