Be sure to add me to your favorites list Casio Battery Cover Door Part for the Casio Casiotone MT-240, MT-205, and MT-820 Electronic Keyboards, May Fit Other Casio / Concertmate Models That Take 6 "AA" Batteries Placed into Two Rows. This is a battery cover for some Casio portable keyboards. It will fit over the battery compartment of some of those models that accept "AA" sized batteries that are placed into two rows inside the keyboard, totaling to 6 batteries. The three models that I know it will fit 100% are the MT240, the MT205, and the MT-820 as I have owned all of those, though there are other models that may be able to use it, as I know there are other Casio models that take AA batteries placed in the same manner inside the unit, and also some Concertmate models as well. The measurements of this part is 3 1/8" inches x 1 1/4" inches, not including the latches. It is in good to very good condition, not warped or cracked, and has it's latches intact. It will complete your keyboard, and keep your batteries inside, with no need for tape. So, replace your lost or broken cover with this one! Thanks for looking! Check out my Store!