Casio CTK-551 Portable Electronic Keyboard

This is a Casio CTK-511 electronic keyboard, a portable digital synthesizer dating from the late 1990s to early 2000s. The unit features 61 full-sized keys and is constructed of a durable black and silver molded plastic chassis. It includes two integrated circular speakers positioned at either end of the control panel, protected by black mesh grilles. The central user interface consists of a green backlit liquid crystal display (LCD) flanked by function buttons, a numeric keypad for tone and rhythm selection, and a volume slider. Notable branding includes the 'CASIO' logo at the bottom and the 'CTK-551' model designation at the top of the interface. This specific item shows practical signs of use; there are handwritten notes or stickers visible on several white keys, likely used as educational aids for note identification. The silver finish on the control panel remains largely intact, though there is minor surface dust and light scuffing consistent with age. According to the user, the internal sound engine contains hundreds of preset tones and rhythms, and the hardware remains in good working order. The build quality represents a standard consumer-grade musical instrument designed for hobbyists and students, offering MIDI compatibility and a variety of digital sound effects.