Casio ABC-30 Calculator Data Bank Watch Module 2332 - Etsy
Amazon.com: Casio SA77 44 Keys 100 Tones Keyboard bundle with Casio Power Supply, John Thompson's Easiest Piano Course and ABC Keyboard Stickers : Musical Instruments
CASIO ABC-31 Calculator Watch Module 2332 | eBay
The Ultimate Guide to the Capabilities and Versatility of an ABC Watch