Function and benefit Use a standard 3.5 mm audio cable to connect the car AUX input to the headphone jack of a CD player, so the CD's audio plays through the car stereo for clearer, louder sound. Battery and performance Rechargeable earphones with up to 8 hours of use on a single charge, providing long listening sessions between recharges. Compatibility and setup Designed to work with devices that have a 3.5 mm headphone jack and with car stereos that accept an AUX input. No Bluetooth pairing or software required; plug in and play. How it solves problems Offers a straightforward wired solution to route CD player audio to a car's speakers, avoiding wireless limitations and ensuring stable sound. Use scenarios 1) Road trips: connect a portable CD player to the car's AUX input to enjoy CDquality sound through the car speakers. 2) Vehicles without a direct CD player: use this setup to leverage your car stereo as the primary listening system for CD audio. 3) Incar demonstrations or events: quickly route CD audio through the car stereo for presentations or testing in a vehicle environment. Notes on design and use Simple, plugandplay connectivity with a rechargeable power source for extended use. Size and material details are not specified.