3M 7100099785 is a wireless earmuff-style hearing protection device with an intrinsically safe design. It has an attenuation rating of 25 dB and features a rechargeable Li-ion pack battery with a life of 8-12 hours. With Bluetooth connectivity and communication capabilities via external 2-way radios, it offers versatile audio options. The hard hat attached suspension method ensures a secure fit. The headset also includes a 4-pin XLR auxiliary port and level-dependent function for ambient listening. Additionally, it has a built-in two-way radio and a dynamic microphone. Connector sizes are 1.6 mm metric and 0.062 in imperial.