Polyplanar 8" 100watt Compact Box Subwoofer with Amplifier This Subwoofers size enables it to be easily mounted below seats (internally & externaly), under gunwale areas, behind instrument panels, under beds or any convenient location. The sub is a self contained unit requiring no cutting of panels of facias to mount. It produces solid bass extending down to 40Hz and is the perfect addition to any audio system, enhancing its performance tenfold. Features include Corrosion proof design and construction for marine use Internal crossover and equalization matched to marine acoustics. Internal distortion limiting circuit will accept line or speaker level input Gain level control to match output to main system Dedicated amplifier is included.