Sharp Gf-7300 Stereo Radio Cassette Boombox Rechargeable Lithium Ion Modded. Cleaned and serviced including new belts. Everything working. Sounds very good and clear. The battery mod is protected with over and under charge circuit. Simply needs to be plugged in with cord and will charge automatically. It is internal without any cosmetic changes or destructive internally and can be easily undone. Lasts for a VERY long time. I couldn't kill it even after using it for several hours every day for a week. Any questions feel free to ask.