Sennheiser HD 450BT Active Noise Cancelling Bluetooth Headphones - SpatialOnline
Sennheiser HD 450BT Wireless Headphones, with active noise cancellation, White: Amazon.co.uk: Electronics & Photo
ANC Headphone Comparison: Sennheiser HD 450BT vs Teufel Real Blue NC - NotebookCheck.net Reviews
Sennheiser HD 450BT Review: Compact & Comfortable - Tech Advisor
Canterbury HiFi | Sennheiser HD 450BT Black Bluetooth Active Noise Cancelling Wireless Headphones | Independent HiFi, Audio/Visual & TV Supplier | Canterbury Kent
Sennheiser HD 450 BT : Bluetooth wireless audio headphones