Be sure to add me to your favorites list Original Casio WK-1800 WK-1630 WK-1600 Keyboard Users Guide Owner's Manual. This is an original full User's / Operation Manual for 3 of the CASIO WK model synthesizer workstation keyboards, the WK-1600, the WK-1630 and the WK-1800. It's quite large for a Casio manual, as this is one of Casio's great sounding Digital Workstation Keyboards, and you need the manual to get the most out of it. It's used but in good condition. This is a very helpful owner's guide, thank you for looking! Check out my other items!