First item: Advanced scientific calculator Casio fx-991ES PLUS, featuring the Natural-V.P.A.M. display system and dual power (solar and battery), it is ideal for high school, university, and science majors. Second item: Reliable classic scientific calculator Casio fx-82MS with S-V.P.A.M. system, characterized by durability and ease of use, excellent for middle school, high school, and daily study.