Amazon.com: Speaker Battery for Harman/Kardon Onyx Studio 4 Onyx 4 ICR22650 : Electronics
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ZZcell Battery For Harman Kardon Onyx Studio 5, 6, HKOS6GRYSG, HKOS6BLKSG, ID997 | eBay
Amazon.com: HQRP Battery Compatible with Harman Kardon Onyx Studio, Onyx Studio-2 Studio-II, Studio-3, Studio-4 Wireless Bluetooth Speaker System LI11B001F : Electronics