The Studiologic SL-880PRO is a Master Controller keyboard that will allow you to split or layer up to four sounds, with powerful expressive control over each.With the SL-880PRO, MIDI beginners can glide easily into their new music endeavor while MIDI pros can use it as a full-featured instrument for composition, as well as stage and studio performance.SL-880PRO provides an 88-note keyboard with weighted hammer action keys for true piano feel, with Channel Aftertouch for expressive control. The patented weighted hammer action provides the pianist with true piano feel and zone specific velocity settings allow a wide range of control over the velocity response of the keys.