Huge impacts - like having a 4 foot antenna on your cell phone. Improves reception, reduce static in boats, elevators, cars, buildings, tunnels, and mountains. Works on any analog, digital, and tri-band phones. Eliminate dropped calls. Easy to install, simply peel and stick to the inside of your battery compartment. Type: signal enhancement Model: 12 Style Weight: 18g Package Includes: 1 PC signal enhancement