This bulk set is ideal for a whole classroom or kindergarten.  It is easy to put the pieces together using the chunky triangles and squares.  It is made from super durable polypropylene and designed to allow the easy construction of thousands of exciting models such as cars, planes and other fun models. Children will love to create vehicles and add the child and adult figures to their creations. Children will develop an understanding of how things work. They will learn how to grab, pull and push their models, which helps with their co-ordination and synchronises movement.  This set includes a leaflet with assembly instructions and model ideas.  Sides of squares measure 5.5cm.  Age 3+. The Junior Polydron Class Set has 372 pieces: 45 Triangles, 45 Triangles with Hole, 9 Axle 120mm, 9 Axle 170mm, 18 Child Figures, 18 Adult Figures, 90 Squares with Hole, 90 Squares, 36 Spacers and 12 wheels.t.