New Walker’s XCEL Muff Series also includes four listening modes: Universal, Speech Clarity Mode, Hi Frequency, and Power Boost. New ergonomic headband design for maximum comfort every time. Hi Gain Omni Directional Mics with Active Dynamic Sound Suppression and Wind Noise Reduction. Controls moved to headband resulting in less holes in ear cups and improving NRR. Powered by 2 (AAA) batteries -included. Hi Gain Omni Directional Mics with Active Dynamic Sound Suppression and Wind Noise Reduction Controls moved to headband resulting in less holes in ear cups and improving NRR Powered by 2 (AAA) batteries -included.