We upgraded to the retractable metal hook,will be much strong,make the phone holder stay in the place. We increased the maximums extendable length of the hook so that it can fit more car vents; also reduced the height of the hook to making it and remove. With its simple designs and easy installation process,this base for car air vent phone holder is a must-have accessory for any driver. It will never fall offs from the car air vent,it can hold your phone in the place securely and firmly. Standard 17mm diameter joint Round can suitable for most car phone holder and wireless car Charging mount.