Be sure to add me to your favorites list Yamaha Replacement Volume and Parameter Knob Part for the MX Series: MX49, MX61, and MX88 Synthesizer Keyboards. This is a new, just out of package condition, replacement knob / dial for the Yamaha MX series of keyboards, the MX49, MX61, and MX88. It's one of the real-time control / parameter control rotary knobs / dials that these keyboards use, and the same knob part is also used for the master volume as well (see the snippet of an MX series stock photo below). Unfortunately, these are very easily lost, so here's a brand new replacement! This is in brand new, never used condition, and will fit right onto one of the stems on your MX 49, MX 61 or MX 88, replacing a lost rotary controller dial / knob. This same part is also used on the portatone keyboard model PSR-S670. I have several of these available and you can get one or more. Thanks for looking, Check out my Store!