Casio FX-991EX Classwiz Scientific Calculator 552 Function | eBay
Got ahold of a Casio fx-991ex and CG-50 to match my Classpad II. I'm really impressed with them but there is something about the fx-991ex... (see comments) : r/calculators
Original Casio Scientific Calculator (fx-991EX) (3 Years Warranty) | Rokomari.com