X strap is one of our concepts for improving the first generation in-box strap, we found out that the back of the head play a crucial role of secure HMD, the other research was that the forehead support can disperse the weight of HMD , then we developed the X type strap, which fused the original beneficial and the research outcome, forehead support and locks the back of the head, also the meets the budget limitation, further we corporated with vendor to make up prototype for user trial.