EKSA Noise Canceling Trucker Bluetooth Headset with Microphone Wireless Over Ear Headphones, 99ft Long Wireless Range, Up to 30 Hours of Talk Time, All-Day Comfort Trucker Headset with Mute Button auspowers_batchone 4mm Shank Diameter

4mm Shank Diameter

and you can even write on it with permanent marker

Wide temperature measuring range

Impact resistance

EKSA Noise Canceling Trucker Bluetooth Headset with Microphone Wireless Over Ear Headphones, 99ft Long Wireless Range, Up to 30 Hours of Talk Time, All-Day Comfort Trucker Headset with Mute Button auspowers_batchone 4mm Shank DiameterEKSA Noise Canceling Trucker Bluetooth Headset with Microphone Wireless Over Ear Headphones, 99ft Long Wireless Range, Up to 30 Hours of Talk Time, All Day Comfort Trucker Headset with Mute Button Specifications Bluetooth version Bluetooth 5. 0 Bluetooth range 30 meters Talk time 30 hours Music time 57 hours Charging time 1. 5 hours Standby time 165 hours Driver diameter 40 mm Driver impedance 32 15% Driver frequency 20 Hz ~ 20 kHz Driver sensitivity