Check the listing for details. SENA WORK4 PRO BULLPACK WITH EXTENDED BOOM MIC. Condition: New. Listed at 250.00 USD. SENA WORK4 COMMUNICATION SYSTEM ARBORIST LINEMAN UTILITY HARD HARDHAT ALSO KNOWN AS MODEL #51172 **HELMET AND EAR MUFFS SOLD SEPARATELY** The standard SENA kit that TreeStuff installs on helmets, the SENA SMH-10 PRO comes with an exclusive extended boom mic designed to better accommodate use with arborist helmets. Installation is quick and easy at home with any arborist helmet and earmuffs and will allow you to talk to up to four coworkers at once.Talk Time: Up to 12 hoursWeight (Main Module): 58g (2.05oz)Maximum Bluetooth Connections: 4Working Distance: Up to 1.6km (1.0 mi)Charging Time: 3 HoursPhone-type communication (not push-to-talk)Bluetooth 4.1Extra boom microphone - just in case40mm speaker driver unitAdvanced Noise ControlHD Voice for high-quality phone call audioNo more yelling to your coworkers from a treeCOUNTRY OF MANUFACTURE:CNMANUFACTURER PART NUMBER:10S-EMIA:4385-0-153