Yamaha S90 ES 88-Key SynthesizerNotes This listing is being sold as is Missing plastic key, included with board Fully functional. Every key button works. A Yamaha S90 ES 88 Key Synthesizer in Good condition! At Evolution Music, we attempt to highlight cosmetic defects (if any) by picturing every angle of every piece of gear so you know exactly what you are getting. We always picture any and all accessories too. What you see is what you will get so please check out the pictures!