1. Reduces FM 88-108MHz to 76-90MHz (All Channel Antenna), compatible with car audio systems that operate on the lower frequency range of 76-90MHz. 2. Enhances signal reception by adjusting the frequency range, allowing car audio to receive improved FM signals. 3. High-quality construction with safety assurance; each unit is individually tuned to the desired band using precise RF test equipment. 4. Features a red wire for positive pole and a black wire for negative pole, designed for easy installation. 5. Compatible with most Japanese car radios. Frequency Range: 76-90MHz (converts standard 88-108MHz FM signal) Hole Diameter: 1.2cm / 0.47inch Dimensions (W x H): 2.5 x 1.9cm / 0.98inch x 0.75inch Cable Length: 30.5cm / 12inch Color: Black Material: ABS Package Contents: 1 x Car FM Band Expander 1 x Instruction Manual Note: Light and display differences may cause slight variations in color between the product and the image. Measurement may vary by +/- 1-3cm.