The Casio LK-165 Portable Keyboard features 61 keys, up to 400 built-in tones, stereo piano sounds and more. There is a 1/8" (3.5mm) mini input for connecting external portable MP3 players, and a USB port for class compliant MIDI operation. Play along with up to 150 built-in rhythms and accompaniments that follow your chord changes. A built-in 10 second sampler lets you sample clips from MP3 players and other external sources.