The Lenovo Slim Pen (4X81P44052) is designed to be compatible with several devices, but its compatibility with the Lenovo Tab M9 tablet is not explicitly confirmed in official sources.

To determine compatibility, it is recommended to check the Lenovo Tab M9 tablet specifications and consult the compatibility information provided by Lenovo. In general, Lenovo pens are compatible with devices supporting WGP, MPP2.0, AES2.0, and AES1.0 protocols, but it's always best to check specifically for the tablet model in question.

If you have any doubts, you can also check the Lenovo community forum or contact Lenovo customer support for more specific information.