diff --git a/arduino/sketchDistanceSerial-Ultrasonic.ino b/arduino/sketchDistanceSerial-Ultrasonic.ino
index 9256f1c..d29c9d6 100644
--- a/arduino/sketchDistanceSerial-Ultrasonic.ino
+++ b/arduino/sketchDistanceSerial-Ultrasonic.ino
@@ -1,4 +1,3 @@
-
 #include "Ultrasonic.h"
 
 #define echoPin 9 // attach pin D2 Arduino to pin Echo of HC-SR04
@@ -18,7 +17,7 @@ void setup() {
 }
 
 void loop () {
-  distance = sensor.Ranging(CM);
+  distance = sensor.Ranging(CM);  // CM or INC
   Serial.print("Distance: ");
   Serial.print(distance);
   Serial.println(" cm");