The Sennheiser FLX 70 is a Bluetooth headset that features FlexFit design for a customized fit, while DSP noise reduction can block up to 70% of ambient noises. A turnable speaker is offered for optimal fit and it can be used on either ear. Included with the headset are an earhook, 3 sizes of silicone speaker sleeves, lanyard and USB wall charger. The speaker itself employs a semi-open system to provide ventilation to the ear and prevent your ear from feeling plugged. This device was ergonomically designed with the cooperation of William Demant Holding, an internationally recognized health care company.