The keyboard and pen that are compatible with the Surface 9 support the following models respectively:

Surface Pro Signature Keyboard:
- Surface Pro 9
- Surface Pro 8
- Surface Pro X

Surface Slim Pen 2:
-Surface Laptop Studio
-Surface Pro 8, Surface Pro 9
-Surface Pro X
-Surface Duo 2
-Surface Hub 2S

Please contact our product advisors directly. They will be able to answer your questions more individually. https://helpcenter.galaxus.ch/hc...