Features: 1.Fitment: Speaker inactive activation wire harness is replacement for Tesla Model 3 2021. Please confirm whether your model is applicable before buying. 2.Activate Speakers: The original car can only use 8 speakers. With this harness, you can activate 4 inactive speakers on your car (only 4 in versions after March 2020), and you can add 2 more inactive speakers. 3.Better Sound Quality: The upgraded wiring harness does not require additional processing, the wires are thicker, the resistance is smaller, the sound effect is several times higher, and it is safer. 4.Stable Transmission: The same audio cable as the original car is used, the data transmission is stable, and the sound quality is lossless. 5.Perfect Upgraded Accessory: Simple installation without any damage. Give your ears a better hearing experience and enjoy being surrounded by music. Specification: Item Type: Speaker Inactive Activation Harness_x000D_ Material: ABS_x000D_ Fitment: Replacement for Tesla Model 3 2021_x000D_ Note: This wiring harness is a modified wiring harness for 8 speakers to activate 14 speakers. The original car has 8 speakers. In the version after March 2020, there are only 4 unactivated speakers without wiring in the original car, so the general wiring harness is 8 to 12. This wiring harness allows you to activate 2 more rear surround speakers for a better music experience and travel pleasure. Before installation, you need to modify the number of speakers, and then install the wiring harness for modification. Professional installation is strongly recommended.