The fronts are 3.5"s with 4" plastic drivers housed in intriguing enclosures. You'll need to remove the entire lower hush panels just to access them. The rears are 5.25"s with the speaker basket serving as snap-ons for the grills. It also has a shallow mounting depth, thus, spacers are used. I have to say that this generation (2) was by far the hardest to upgrade.