Smart Poly™ material has been designed for the classroom and home. The material is strong, durable, water resistant, and does not need lamination. Heavy duty double-sided surface for fun and colorful learning on both sides. Write-on/wipe-off surface. Use with dry erase or water based markers and washable crayons. Each side is an interactive lesson. Mat measures 12" x 17" . The STEM Education Set includes 4 learning mats: Solar System (95014), Periodic Table of the Elements (95015), Human Body/Anatomy (95019) and Keyboard Basics/Internet Safety (95021).