B&C 21SW152 is a very high power 21" subwoofer for speaker subwoofer systems- B&C 21SW152 21" Subwoofer has a lightweight neodymium magnet - B&C 21SW152 21" high power speaker for speaker subwoofer
B&C Speakers 21SW152 4/ohm - ePRODANCE.cz
2) B&C 21SW152-4 21" Neodymium Subwoofer 4-Ohm DJ Live Sound 4000Watts Bass Sub | Reverb