The Casio MJ-100D Plus is a desktop calculator produced by Casio, a well-known manufacturer of calculators and electronic devices. Here are some features commonly found in the Casio MJ-100D Plus:

1. Dual Power Source: This calculator typically operates on both solar power and battery power, providing users with flexibility in various lighting conditions.
2. Large Display: The MJ-100D Plus usually features a large, easy-to-read display, making it convenient for users to view calculations and results.
3. Functionality: It offers basic arithmetic functions such as addition, subtraction, multiplication, and division, as well as additional functions like percentage calculation, square root, and memory functions.
4. Design: Its design often includes a durable and ergonomic layout with well-spaced keys for comfortable and efficient input.
5. Compact Size: Despite its functionality, the MJ-100D Plus is usually compact and lightweight, making it suitable for both desk use and portability.

Overall, the Casio MJ-100D Plus is designed to provide users with a reliable and convenient tool for various mathematical calculations in both professional and educational settings.