The main function of this type lap top stand as below: 1: three scientific supporting angles to make you ease when you operate laptop. It will protect your cervical vertebra and lumbar from the damage caused by incorrect pose. 2: three scientific supporting angles enable you to operate the laptop in bed, on knee, etc. 3: portable, because the the size only 342mm*244mm*12mm, weight: 556g. it can be put into the laptop bag easily. 4: hollow out design to release heat naturely without extra electrical power, in order to prolong the life of laotop. 5: green material to keep you healthy. Also there are some other accessional function: 1: can be used as bookshelf 2: can be used as tablet 3: key board of desk-top can present the same angle.