The holder is easy to assemble and holds sufficient. However, the retention force for violent shocks is not just enough. Cell 1 (Sony Xperia Z1 Compact) can not secure safe enough with protective cover. The thing is too risky. Cell 2 (Zopo ZP980 scorpio) keeps well without protective cover - however, the side buttons are pressed when the hand is clamped not offset. I use the holder meanwhile the side of the upright handlebar as eyeglass holder - and for this he is really well suited.
