Are these sentences grammatically sound and correct?

The technical details provided do not explain how to fix the lampshade onto the wall light. It seems that It can be only fixed directly to the wall, not onto the wall light. The diameter of the lampshade is 2" shorter than the diameter specified in the technical details
Please confirm whether the wall light with wall mounted shade or the lampshade with fitter one, which can be fixed onto the wall light type.