Feature: 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 Material: ABS Fitment: Replacement for Tesla Model 3 2021 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.. Package List: 1 x Screw Wrench1 x Removal Wrench1 x Speaker Inactive Activation Harness