Moulded from Poly+ material, the lightweight blocks and planks allow for substantial, interactive group builds in muddy, rugged environments. Each piece features thick hollow walls, weather-resistant stainless steel hardware, and soft-touch endcaps that absorb shock as builds are deconstructed during play. This set includes cubes, rectangular prisms, right triangles and planks. Largest block is 11"W x 5.5"D x 5.5"H. Ages 2 and up.