This is the price for three units together. Improves feeling. Enhanced function to reduce electrical load. Effectively brings out the car's performance. ■ Simply plug into the cigarette lighter socket This easy-to-install model utilizes the car's DC power and operates on the Hot Inazuma principle. ■ Negative ion generation function Various effects such as relaxation and deodorization can be expected. ■ Hot Inazuma effect Reduces the load and loss on electrical components and the ignition system, drawing out the car's original performance. This is the "Hot Inazuma effect." Furthermore, it enhances the function to reduce the load caused by instantaneous voltage drops due to "high-frequency noise" generated from the vehicle. Responsiveness is improved. Torque also increases, and the audio's LOW response improves significantly, resulting in a more detailed sound quality, and I felt that the muffled sound was eliminated, although this may vary from person to person. What do you think? I'm open to price negotiations. Thank you.