Subwoofer:SSV Works Premium Marine Sub:(RZ4-GB10A) Our premium Marine subwoofer started the revolution. They produce great volume and clarity for the price and are very reliable. - 10" 600 watt (300w RMS) woofer Kicker Powersport Subwoofer:(RZ4-GB10K) This weatherproof sub is at home on the trail, in the sand and on the road. - 10" 800 watt (400w RMS) woofer Without speakers:(RZ4-GB10U) order em empty. Already have speakers? This is for you.