Yellow Jacket&trade; Rechargeable Battery Pack Stun Gun iPhone Case for 4/4S (White) Concealed inside Yellow Jacket is a loud, bright high voltage stun gun that produces a painful "sting". Yellow Jacket houses a rechargeable battery that virtually doubles the life of your phone. A durable PC & ABS hard plastic case protects your phone from damage. Sharp Electrodes Penetrate Clothing for Maximum Effect