diff --git a/External-LED.md b/External-LED.md
index 9758ca1..b5f933c 100644
--- a/External-LED.md
+++ b/External-LED.md
@@ -22,4 +22,4 @@ NOTE: You will have to modify and re-flash the software to drive this pin instea
 
 # Recommend LED and Resistors
 
-TBD
+https://www.mouser.com/technical-resources/conversion-calculators/led-series-resistor-calculator