Silencer Ear Buds have integrated omni directional microphones and full dynamic range speakers that deliver a crisp clear sound while Sound Activated Compression protects hearing. They utilize OS-R3110 Digital Sound Processing, feature independent volume control, and have an on/off power switch. Along with the advanced technology, Silencer incorporates the Secure Fit system, which includes three sizes of contoured fins and foam buds for a customized fit. The Silencer ear buds offer a 25dB NRR, and up to 80 hours of battery life, powered by #10 batteries (4 included). These ear buds are matte black with carbon fiber accents, and include a removable lanyard and carry case.The Bluetooth model features an advanced digital circuit, voice prompts, and has three program settings: noise filtering (voice clarity), HI frequency boost, and power boost. It is rechargeable and uses a USB charging dock with integrated Lithium battery. A USB cable is included.