DESC: Works on all digital, analog cell phones eg. (Nokia, Samsung, Nokia, Motorola..etc). It increases the signal strength on your cell phone. It's Like having a 4 foot long antenna. Now you to talk on your cell phone in elevator, car, tunnel. And building more clearly. Reduce static in low reception area. Easy to install, comes with instructions. A great gift for friends and family with cell phones. Instructions included on package. No tools needed. Just peel the adhesive seal of the Antenna Booster. Open your cell phone battery. Attach onto the back of your cell phone or cell battery. That's IT !