[pdreher]

ok the ones in the front are 3 1/2! And you can use a screwdriver to get the cover off. now the bezel over the radio is a little tricky. the part that has the heater controls on it has to come off 1st i took mine off with a flathead you can pry to off. there is probably an easier way to do it but that is what i did, then you have 4 screws to take off, 2 in the top and 2 in the bottom of it. the rear speakers dont know what size they are i would guess 5 1/2 but not sure. well that is what is in my 96 Tracker.