Give your iPhone GPS, podcasts, and phone calls a sound boost. The built-in amplification system in the cradle doubles the volume coming from your iPhone speaker, making it easier to hear your turn-by-turn directions, calls and more. The cradle mounts in seconds to the windshield or vent and holds your iPhone securely on even the roughest terrain. Includes both windshield and vent mounts. Cradle amplifies iPhone speaker for twice the volume with no added battery drain. Cradle mounts in seconds to the windshield or vent and holds your iPhone securely on even the roughest terrain. Cradle pivots for vertical or landscape modes. Flexible arms securely hold your iPhone-even when in a case. NOTE: Because the design of cases can vary from brand to brand, the acoustic amplifier may not perform as specified when a case is used.