Car Auto Vehicle Signal Strength Booster Repeater Antenna for Cell Phone Phones Use in your car to improve signal strength. Helps to prevent signal loss and dropped calls. Extends the distance of both incoming and outgoing signals from your cell phone. Easy to use: No tuning or initial setup/syncronization required! Easy to Install: Sticks right onto your car window without having to drill holes or run wires. This passive-repeater circuit board will reduce signal loss, cutoff/call drops, fade, and static while your using your phone.