Features:- Easy to mount on your car chair back splint- Stretchable clamp from 20 to 33cm- Suitable for putting 7" to 10.1" devices- 360 degree rotate for different directions viewing- Enjoy the pleasure of using tablet PC while taking carInstallation Steps:1. Put the headrest mount into the two steel pipes of the front seat headrest2. Make the X or Y type fixed bridge combined with head stents3. Loosen the rod behind the fixed bridge， adjust the height and depth， and fasten tie the rod only