Warm Tips: For Dashboard/Windshield Mounting 1. Do not install the suction cup on curved/rough/dirty surfaces. 2. When summer approaches or days are getting hotter, please avoid constant direct exposure to the sun as this may affect the performance of your phone holder for car. 3. Push the lock lever down to lock the suction cup after installation. 4. Please tighten the knob on the telescopic arm after adjusting the angle.