Like New (never used) with this exception: Practice book 4A has pencil entries on the first 5 pages.
From the publisher's website (Art of Problem Solving/Beast Academy):
Level 4 Math Books
Ages 9‑12
Learn exponents, factors, integers, and more with Beast Academy Level 4 curriculum. Includes guide books and practice books for all four units (4A-4D).
Designed in an engaging comic-book style format, Level 4 curriculum includes the Guide books and Practice books for all four units (4A, 4B, 4C, 4D).
The Guide books are full-color paperback textbooks, which teach concepts in a comic-book style.
The Practice books complement the Guide books and includes 300+ problems ranging from introductory-level exercises to challenging puzzles and word problems.