145Pcs Marble Building Set Includes Various Color Tracks,Magnetic Block, Marble, Polygon, Stickers. Your Kids Can Build Anything According To Their Own Ideas. Each Piece Of This Magnetic Building Blocks Contains Permanent Magnets, Stable Magnetic Force, Strong Adsorption, So That Children Can Easily Assemble The Shape, And The Shape Is Stable. This Makes The Playability Greatly Improved, The Whole Process Of The Ball Rolling Is Unimpeded, And Children Can Change Entrance And Exit,The Speed Of The Ball Through Changing The Structure. The 3D Magnetic Tiles Are Made Of Durable Abs Plastic. Stronger Magnets Allow Kids To Build Easier And Faster. Smooth Surface And Round Edge Design Protect Your Kids From Scratching.