diff --git a/Update-firmware.md b/Update-firmware.md
index 11226cb..599b68b 100644
--- a/Update-firmware.md
+++ b/Update-firmware.md
@@ -2,7 +2,7 @@
 Giving the fact that too much people still having issue reading this guide, please carefully read this chapter so you'll know basic concept of how to update.   
 **Please note that this chapter is just for making the concept clear, you still need to read all other chapter below for detailed guide!**  
 The basic updating procedure can be simply done by following two steps:  
-1. Update your sdcard content. This need you copy about 2 GB files, which is recommend to pull out your sdcard and use a sdcard reader on computer to copy files.
+1. Update your sdcard content. This need you copy about 2 GB files, which is recommend to pull out your sdcard and use a sdcard reader on computer to copy files. (You don't need to do this every time, since the sdcard content won't change much. However if sdcard content changed in the new release, you should do it.)
 2. Update firmware + external apps. This can be done by following ways (pick one of them):
 
     * On a computer, enter HackRF mode, flash with a usb cable, then copy and paste external apps into sdcard.