High Grade Robust 360° Adjustable Car Windshield Swivel Suction Mount with Low Profile Car Kit Holder for 7" Tablet PCs
It branded Arkon , very stable,good quality,holds 7inch or iPhone very firmly.it has big suck cup,that might be the reason for stable. So you can use it for 7 inch tablet or 4 inch iPhone ,love it ,only thing can improve is when you lock the position it is not easy to adjust,for example when you turn your iPhone form landscape to horizon position ,it will loose ,you have to tighten it again.