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 NA LLC 21SW152-4 21 in. Neodymium Subwoofer - Walmart.com
B&C Speakers 21SW152 4/ohm - ePRODANCE.cz
2 X B&C 21SW152-4 21" ported build, 15cu.ft per | Page 5 | AVS Forum