Rugged Radios HK-OFSP-3.5-AA ALPHA AUDIO OFF ROAD HELMET KIT WITH SPEAKERS MIC & 3.5MM EARBUD JACKRugged Radios HK OFSP 3. 5 AA Designed for high performance off road use, the RUGGED Wired Helmet Kit with Alpha Audio speakers delivers clear audio for both communication and music. As part of the Rugged Wired lineup, this kit is ideal for work, race, or playoffering a reliable solution trusted by racers and recreational drivers alike. Alpha Audio helmet speakers produce full range sound with enhanced highs and lows Dynamic noise canceling microphone