diff --git a/hardware/frame/v2.0/readme.md b/hardware/frame/v2.0/readme.md
index 109e876d..b5828009 100644
--- a/hardware/frame/v2.0/readme.md
+++ b/hardware/frame/v2.0/readme.md
@@ -9,3 +9,5 @@ The source is availale at:
 https://cad.onshape.com/documents/ba47819ff100597297d1d967/w/f19409ec7cd5459afb429cb9/e/a0e0cc37dee6fb879c4bcc2b 
 https://cad.onshape.com/documents/1515e31c7fa5f6258ef39ae7/w/36f6069826ee0c0263f8d85e/e/2b7801717a8e1af3df455057
 https://cad.onshape.com/documents/188300bd4469521b14597507/w/546e1730182c1520c46b050d/e/ceef7084a00eb9b26c486bb6
+
+To make a 2U frame, also print the 2U connector part in https://github.com/alanbjohnston/CubeSatSim/tree/master/hardware/frame/v2.0/2u and print two additional side parts.  See https://github.com/alanbjohnston/CubeSatSim/wiki/Upgrading-to-2U for more information.