The S midheaven board, is aims at the traditional PC midheaven board deficiency, the improvement is the S board. The traditional midheaven board fulcra is a rectiunear figure, is unable regarding the pressure to proliferate evenly to the pan. Nowadays the fulcra improvement is S, but the pressure diffusion to the pan, resistant to compression increases evenly. Moreover, the S midheaven board's fulcra is the round campylodromous, may the intense sunlight refraction be the soft light.