With this 398 piece giant red and white blocks set, you can build a large tunnel (If using the included plans, once built the tunnel will measures 120 x 68 x 100 cm), it comes with full plans and pictorial instructions on how to build it. Each robust block has an interlocking design and measure 20 x 10 x 7.5 cm. It is suitable for indoor and outside use. Further plans can also be drawn up and the building blocks in the set can then be used to build almost any other structure in your childs imagination. For ages 10 months and over. WARNING(S): Only for domestic use. To be used under the direct supervision of an adult.