Speaker Inactive Activation Wire Harness 14 Upgrade Audio Modification Harness Replacement for Tesla Model 3 2021 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.