Universal Mode: The universal mode allows sound amplification Power Boost Mode: The Power Boost mode amplifies sound across the range of volume High Frequency Mode: This mode is tuned specifically to hear steel target impact at long distances Speech Clarity Mode: This discriminates voices and enhances verbal communication in a noisy environment Bundle Includes: Walkers XCEL 500BT Digital Bluetooth Electronic Muff with Listening Modes (OD Green), and Walker's Shooting Hearing Protection Case (Black)