REL Arrow Wireless Receiver for REL Subwoofer - Gen 2 - READ | eBay
Rel Series T/i Powered Wireless Subwoofers Preview | Audioholics
Amazon.com: REL Acoustics Airship™ Wireless Subwoofer Transmitter Created for 212/SX, S/510 and S/812. Compatible with G1 Mark II. Not Compatible Serie T/i, Serie HT, Legacy Serie S or No.25. : Electronics