No person wants to be kicked at full power so we have variety of boards with different strengths that you can practice and improve your technique to be sure that your kicks are truly effective - These boards are terrific value because they have a shaped joint so that you can put them back together and keep using the board many years -- SIZE - This Board is White with a dense foam Blue cover on both sides it is 31 cms tall by 23 cms wide -- STRENGTH - Because the boards are made in a machine the strength will always be the same - BUT the strength of wood can vary and this White Board is approximately equal to a dry piece of Parana Pine that is 13 mm thick -- NOTE - That there is nothing worse that not succeeding so we always recommend that you start with a low strength board then progress to stronger boards as your technique improves -