Hifonics ZRX12 Dual – 2x 30 cm/12 inch Bandpass Subwoofer Enclosure Dual Bandpass System : Amazon.de: Electronics & Photo
Amazon.com: Audiotek AT-210WS Dual 12" 1400 Watts Max Power Band Pass Vented Sealed Premium Vehicle Sub Box Loaded with 12 Inch Car Audio Dual 4 Ohm Subwoofer Enclosure : Electronics