4C IMSA Wired Coil Cord Helmet Kit with Mic and 3.5mm Jack is designed for road racing and offers clear, loud audio suitable for driver communication. Commonly used in open-wheel and sports car series like LMP2, GT3, GT4, and TCR, the kit has a 4-conductor IMSA configuration. It easily installs into most helmets and comes with a dynamic noise-canceling mic, full-flex boom, a coil cord, and a 1/8in jack for earbud connection. The kit is compatible with standard IMSA car harnesses using a 4-conductor plug and requires mono earbuds for models with a 1/8in jack. Mic boom and cable junction block install using hot glue or Rugged Quick Mount for a neat, effortless installation.