diff --git a/src/Servo.h b/src/Servo.h
index 53ecb8e..4898ca7 100644
--- a/src/Servo.h
+++ b/src/Servo.h
@@ -82,6 +82,13 @@
 #define MIN_PULSE_WIDTH       544     // the shortest pulse sent to a servo  
 #define MAX_PULSE_WIDTH      2400     // the longest pulse sent to a servo 
 #define DEFAULT_PULSE_WIDTH  1500     // default pulse width when servo is attached
+
+                                      // default frequency - servos within kits
+                                      // 20000µs/1000000µs = 0.02s
+                                      // 1/0.02s = 50Hz
+
+                                      // higher end servos - remote control servos --- typical 333Hz
+                                      // 1/333Hz = 0.003003s * 1000000µs = 3003µs for a refresh rate
 #define REFRESH_INTERVAL    20000     // minimum time to refresh servos in microseconds 
 
 #define SERVOS_PER_TIMER       12     // the maximum number of servos controlled by one timer