For use with Peltor™ headsets as an alternative to the ANC RSM. Attaches directly to the side connector of the MOTOTRBO DP4401EX / DP4801EX or TETRA MTP8500EX / MTP8550EX radios. Compatible with Peltor Headsets PMLN6087, PMLN6092, PMLN6333, PMLN6090 and PMLN6089.