ROCKBROS bicycle phone holder bag is made of high quality waterproof material, together with rubberized waterproof zipper preventing your phone from rain, water and dust. On the inner layer, the thickened sponge shows a good performance of shock aborption. Carbon texture surface fit waterproof upgrade, the tool-free mounting bracket is quick, stable, humanized shading board, 360 Degree + multi-wide view up and down adjustment.