diff --git a/doc/hid_downgrade.md b/doc/hid_downgrade.md
index 5fdd06655..2ede7a422 100644
--- a/doc/hid_downgrade.md
+++ b/doc/hid_downgrade.md
@@ -241,6 +241,7 @@ IT IS ABSOLUTELY NECESSARY THAT THE READER AND ESPKEY SHARE THE SAME GROUND EVEN
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 OBS!  Downgrading to a T5577 will only work if reader has low frequency (125 kHz) / Prox II enabled.
+A good indicator to look out for is the "MultiClass" sticker on the reader.
 
 ## Using Proxmark3
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