Sennheiser's PXC 550-II Wireless Headphones are Built for Travel
Sennheiser PXC 550-II review: Great sound and ANC - SoundGuys
Sennheiser PXC 550-II Wireless NoiseGard Adaptive Noise Cancelling Open Box NEW | eBay
Amazon.com: SENNHEISER PXC 550-II Wireless NoiseGard Adaptive Noise Cancelling, Bluetooth Headphone with Touch Sensitive Control and 30-Hour Battery Life, Black : Electronics