Yamaha Arius YDPS52 Traditional Console Style Digital Piano, Black PureCF sound engine delivers well-balanced, rich, expressive Voices A Synthetic Ivory Graded Hammer (GH) keyboard provides authentic acoustic piano playability and comfort Reverb that reproduces the distinctive ambience of a wide range of performance venues Unique to Yamaha, the Stereophonic Optimizer adjusts the sound when listening via headphones Simple operation using the free Digital Piano Controller app!