Before installing, peel off the sticker.The surface should not be dusty, oily, wet or polished. Clean it with dry cloth before mounting. Suction gel pad can be washed with normal water and let it dry in natural air. Once done, it will regain its sticking gel and it can be stuck anywhere. There is a dual lock technology ABLE. Use only First lock if mounting it on glass panel and apply Second Lock if using on dashboard."