diff --git a/README.md b/README.md
index 467db66..38dccb6 100644
--- a/README.md
+++ b/README.md
@@ -31,8 +31,24 @@ joint the projects community [Discord Server](https://discord.gg/maRvMVpa2Q).
 4. Change the hardware configuration according to your build [hw_config.h](firmware/MotionControllerRP/src/hw_config.h)
 5. Upload firmware using VSCode with PlattformIO plugin
 6. Calibrate axis
+7. 
 
-## ✨NEW: Open Micro-Manipulator GUI
+## ✨NEW: Hardware Version 4.0
+A new version of the hardware has been released, fixing several issues with the previous design:
+
+- Self collision during homing fixed.
+- Connection of ball joint block with screws only was not well constrained and could rotated a bit.
+- No reliable way to ensure consistent linkage rod length
+- Unnecessary ball joint friction
+- Accurate ball position heavily dependet on print quality and corner rounding
+- Rubber bands could not be changed or removed once glued in.
+
+A video about the improved ball joint and linkage manufactoring process can be found on YT: [Better Ball Joints for the Open Micro-Manipulator](https://www.youtube.com/watch?v=NM2KXvRGmpg)
+Also the FreeCAD model was restructured and improved and now includes all pins and fasteners. It now provides a reference for all required mechanical parts. 
+
+WARNING: BOM is not updated yet...
+
+## Open Micro-Manipulator GUI
 To make testing and using the Open-Micro Manipulator easy and convenient a python control program with a graphical user interface is provided here: [Open Micro-Manipulator GUI](https://github.com/0x23/OpenMicroManipulatorGUI).
 It has simple controlls to move the device around, while also displaying a live camera feed (e.g. from a microscope camera). Additional features, include a simple g-code runner and realtime mouse control (e.g. for Biology applications).