Boost the sound and down out the road noise with the this JBL Audio Speaker upgrade. Building products for 70 years JBL has been a magnet for music lovers of every generation. JBL acousticians, mechanical experts and software engineers have modified and all audio elements of Cardo's intercom systems to deliver a whole new 45 mm set of the best sound ever in a motorcycle communication system; 45mm Speaker Upgrade 42mm Base Optimized for Cardo's Freecom and Packtalk series Works with other audio systems equipped with a standard 3.5mm audio jack