TI-84 Plus Keypad interchangeable keypad designed for the TI-Nspire and TI-Nspire CAS calculators.

Here's what to know about it:

Purpose: It turns your Tl-Nspire into a fully functional TI-84 Plus calculator (it runs the TI-84 Plus OS when this keypad is installed).

Compatibility: It only works on the original TI-Nspire Clickpad model (not the newer Touchpad or CX II versions).

Usage:

a. Power off the TI-Nspire.

b. Slide off the Nspire keypad.

c. Attach this TI-84 Plus keypad until it clicks in.

d. Power on — it'll boot into the TI-84 Plus operating system.

So in short, this keypad gives your Tl-Nspire the same interface, menu behavior as a TI-84