SRC Pro Challenge II Racing Earbuds - Made in USA ( Black) 

Pro Challenger II (Made in the USA) Racing Radio Earbuds Foam Tip Buds Acoustic Tube 3.5mm Jack High Quality Transducer Knowles Very small Foam Tip design w/ hearing aid transducers that pipe the voice straight into your ear canal offering clear radio communication under true racing conditions Made in the USA

Racing earbuds and helmet speakers plug into your helmet kit's 3.5mm jack so the driver can hear the crew clearly over engine noise. Earbuds seal out more noise in loud cars; helmet speakers are simpler to live with.