This Impact Sport earmuff has a 21 dB Noise Reduction Rating (NRR) and a digital compression circuitry with 5X sound application. It features a faster sound activated compression, at a 0.5 millisecond reaction time. Equipped with BluetoothA(R) technology, this allows you the ability to sync your wireless devices to the earmuff. The headset has separate volume controls for BluetoothA(R) and external environment amplification. External environment amplification uses a 2-high gain direction microphones. Impact Sport earmuff has AIR FLOW CONTROL that allows for a slim low profile ear cup design ensuring firearm stock clearance. Adjustable headband now available in two different sizes for a more custom, secure fit and a compact folding design for convenient storage. Automatic shut off engages after 4-hours to conserve battery life. Comes with a rechargeable lithium-Ion battery with USBC recharging cable.