H85 Linkable Full Duplex Intercom Headset features reliable, constant communication over noise, safeguarding your hearing at the job site. It uses daisy chain technology to link unlimited headsets for hands-free communication, ideal for job sites where wireless communication isn't an option. The Behind-The-Head design ensures rough environment compatibility and works with hardhats and various other types of headwear. The H85 employs dynamic noise-cancelling for optimal voice clarity, designed to withstand harsh work environments. Demands dual 9V batteries for extended talk time and has a 24 dB Noise Reduction Rating (NRR). You can link to one or more H85 headsets and provides compatibility with other manufacturers' linkable headsets such as Avcomm, Racing Radios, Track Scan, Racing Electronics, and many more.