12" subwoofer. 90 watt amp. Unlike most subwoofers today, this one has a high pass filter and dual RCA line input. You may use it to take the load off smaller main speakers to enhance their performance and for better integration. It also has a switch for Audio or Video playback so you can use it for music or movies. This is a heavy beast. This is not without issues though. It is a little beat up (but it's a sub that you can hide somewhere) It powers on and some sound comes out of it, but when you try and adjust the variable crossover, you get a scratchy sound. It may just need cleaning of the switch but I don't have the time or room for this.