These headset are really cool. They’re sound-isolating, with electronic voice pass-through that automatically cuts off sounds above a certain decibel level. High-speed units will wear them all day while conducting an operation, allowing the operators to hear everything going on around them, carry out normal conversations, and still protect their ears when things get spicy. Addition of wiring for radio comms further increases the individual Soldier’s ability to communicate over the radio. 

I’ve included pictures of the set I “acquired,” paired with a PRC-128.