Welcome! I am unsure of the period of use or frequency. *Please check carefully as items not listed are not included.* Included items: Main unit only Condition: Operation has been confirmed! There are scratches on the body. We have cleaned and disinfected as much as possible with a dedicated cleaning solution. *We are also listing on other sites, so please confirm with a comment! Also, this page will be deleted once a deal is made.* #Tombow #Harmonica