diff --git a/frc971/constants.h b/frc971/constants.h
index 890c63c..ad3ce71 100644
--- a/frc971/constants.h
+++ b/frc971/constants.h
@@ -16,6 +16,15 @@
   double allowable_encoder_error;
 };
 
+// Defines a range of motion for a subsystem.
+// These are all absolute positions in scaled units.
+struct Range {
+  double lower_hard;
+  double upper_hard;
+  double lower;
+  double upper;
+};
+
 }  // namespace constants
 }  // namespace frc971