Use to add aftermarket speakers to factory door location. Speeds up installation time. Includes two pair for four doors- 4 plates and 4 speaker harnesses. Works with most 6 inch, 6.5 inch, and 6.75 inch speakers. Aftermarket speakers vary in size, width, depth, etc so even though it might be listed as a 6", 6.5" etc speaker, some speakers might require modification of the speaker adapter which is normal. Compatible vehicles: Made for Infiniti: 2003-2008 FX35 Front and Rear, 2003-2008 G35 Front and Rear, 2007-2015 G37 Front and Rear;; Made for Nissan: 1995-2018 Altima Sedan Front and Rear, 2009-2014 Cube Front and Rear, 2009-2015 GT-R Front and Rear, 2011-2024 Leaf Front and Rear, 1995-2016 Maxima Front and Rear, 2004-2016 Quest Front and Rear, 2007-2018 Rogue Front and Rear, 2007-2024 Versa Front and Rear, 2014-2019 Versa Note Front and Rear