JL Audio MHD600/4 600W RMS 4-Channel Marine HD-Series Amplifier Rated Power (4 Channel Mode): 150 W RMS x 4 @ 1.5 ohm-4 ohm (11V-14.5V) Rated Power (Bridged to 2 Channel): 300 W RMS x 2 @ 3 ohm-8 ohm (11V-14.5V) THD at Rated Power: &lt;0.03% @ 4 ohm per ch. Dimensions (L x W x H): 10.74 in. x 8.29 in. x 1.93 in.