This is a cloth intended to clean your cue. From the well-known brand "Molinari". When you have cleaned your cue with this you can, for example, apply a protective layer with the "Molinari Cue Wax". Or you can use the cloth to apply the "Q-Doctor cleaner & conditioner" to your cue.
Together with the aforementioned products perfect and indispensable for the maintenance of your cue.