Philips provided the SHB9850NC headphones free of charge after the Bluetooth left hand channel failed on the Philips Fidelio M2BT headphones supplied by Amazon Vine.
These are on-ear headphones with active noise cancellation using two external microphones and two microphones within the ear cups. External noise that can be heard in the ear cups is inverted so that the external noise is cancelled out. Philips claims 99% (-20dB) reduction of background noise. The drivers within the ear cups are 40mm with a claimed frequency response of 8Hz – 23.5kHz, but it does not state the deviation from a flat response. Controls for play / pause, volume, skipping tracks and phone calls are by tapping or sliding a finger on the outside of the ear cup.