1 files changed, 1 insertions, 1 deletions

diff --git a/README.md b/README.md
index a8dd221..a1acc2d 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@ usage: calctenna.py [-h] [-f [frequency]] [-V [velocity_factor]] [-q]
 optional arguments:
   -h, --help            show this help message and exit
   -f [frequency], --frequency [frequency]
-                        desired frequency in Hz
+                        desired frequency in Hz (e.g. 144800000 or 433e6, ...
   -V [velocity_factor], --velocity-factor [velocity_factor]
   -q, --quiet           print only result
 ```