Birchwood Casey's eKrest Electronic Muff has an NRR rating of 26dB, and attenuates all sound above 85dB. It has an on/off switch with volume control for variable sound amplification, and two omni-directional microphones. The eKrest muff also has an auxiliary input jack and includes an auxiliary cord. It runs off of 2 AAA batteries, which are included. This model has a black carbon fiber finish.