Thomann Cover Pro dB FlexSYS FM10

This cover fits perfectly and keeps the dust off the stage monitor.
It is of limited use as it is not padded and only covers the top and sides of the cabinet (not the back) and only if it's on the floor, you can't use it if the monitor is on a stand, for example.
However, if you're looking for a relatively cheap way to cover your FlexSYS FM10 monitor when you leave it in your rehearsal space, this does the job well and more attractively than a plastic bag.

A small investment to keep a great speaker looking good forever.

Did the job, sturdy, Professional. What more is there to say.