Walker's Xcel 100 Digital Electronic Earmuffs - 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. Advanced Digital Circuit Active Dynamic Sound Suppression Hi Gain Omni Directional Mics Wind Noise Reduction Voice Mode Navigation Auto shut off 2/4/6 hours Controls moved to headband Less holes in the muff cups to improve NRR New ergonomic head band design Rubber bumpers on lower cup Low battery warning