The Carson Sound Module for On Road R/C Cars is super small, easy to use and easy to install. A microprocessor reproduces the sound recorded on real vehicles via a miniature speaker. Specs: Compatible with brushed & brushless models Input voltage 6-12V Continuously adjustable volume Comes with TAMIYA plug Sound Unit Dimensions: 90x40x28mm Weight approx 83g Manufacturer: Carson Model: C906265 Sound Unit for On Road Car