Question about Lenovo 4x40n18009

The outside pocket (with zipper) has plenty of room for a radio mouse, net cord, etc.

The ThinkPad 14" protective case (4X40N18009) fits up to 344x247x24mm and is therefore a little too big for an X1 Yoga 2nd Gen (333x239x17.4mm).
The X1 Yoga 2nd Gen then 'floats' around a bit in the case.
For additional accessories, the protective case has an outer pocket that should fit a charger and wireless mouse.

I had to exchange the ThinkPad 14" protective case (4X40N18009) for my X1 Yoga 6th Gen 14" (313x223x15mm), which was clearly too big, for a ThinkPad 13" protective case (4X40N18008), which fits up to 322x223x20mm. Again, the X1 Yoga 6th Gen still 'floats' a bit in the case in one direction.
I can easily stow the charger and power cable for my X1 Yoga 6th Gen in the outer pocket. I don't have a wireless mouse. (Why do you need a separate mouse for a ThinkPad? With a little practice, the red TrackPad is a perfect mouse).

As the Lenovo forum also shows, there are unfortunately no really perfectly fitting protective cases for the X1 Yogas.