diff --git a/Htmldocs/release_notes.html b/Htmldocs/release_notes.html
index df148ffb..a92781c6 100644
--- a/Htmldocs/release_notes.html
+++ b/Htmldocs/release_notes.html
@@ -15,6 +15,11 @@
     <br>Portions of OSCAR are © 2019-2022 by
     <i>The OSCAR Team</i></p>
     <ul>
+      <li>[new] Additional Philips Respironics devices tested and fully supported:
+        <ul>
+          <li>DreamStation 2 Auto CPAP Advanced with P-Flex (521X120C)</li>
+        </ul>
+      </li>
       <li>[fix] File Export Sessions now exports statistics session data properly.</li>
       <li>[fix] Fixed a rare crash on import when encountering corrupted Philips Respironics directories.</li>
     </ul>
diff --git a/oscar/SleepLib/loader_plugins/prs1_loader.cpp b/oscar/SleepLib/loader_plugins/prs1_loader.cpp
index e04d0149..5d806da1 100644
--- a/oscar/SleepLib/loader_plugins/prs1_loader.cpp
+++ b/oscar/SleepLib/loader_plugins/prs1_loader.cpp
@@ -133,6 +133,7 @@ static const PRS1TestedModel s_PRS1TestedModels[] = {
     
     { "520X110C", 0, 6, "DreamStation 2 Auto CPAP Advanced" },  // based on bottom label, boot screen says "Advanced Auto CPAP"
     { "520X150C", 0, 6, "DreamStation 2 Auto CPAP Advanced" },  // from user report
+    { "521X120C", 0, 6, "DreamStation 2 Auto CPAP Advanced with P-Flex" },  // inferred from 501X120 and presence of "P-Flex" on bottom label
 
     { "950P",    5, 0, "BiPAP AutoSV Advanced System One" },
     { "951P",    5, 0, "BiPAP AutoSV Advanced System One" },