1 head unit-cd player with an mp3 input jack,wiring kit-power wires ground wire and rca"s. front stage speakers prefer full range speakers.,rear stage speakers,battery terminal connector, a capacitor if over 500 rms, 2 sub-woofers in a sealed box. both subs need to be single voice coil 4 ohms wired in parrell for a 2 ohm load on the amp. one mono amplifier and a lot of sound deadening. good luck.
