When you move, it doesn’t. Trigger the Aero Flex rail to stabilize the Trainer – so you can stay focused on pushing your limits. No cables to hold you back. Enjoy your music with Bluetooth technology, while maintaining incredible sound quality. Weather Seal ensures the Trainer is protected from water and sweat – so you can run hard, rain or shine. Activating SafeSound turns down the volume and reduces the bass so that you stay alert to your surroundings. Products with Outlast technology respond to your constantly changing skin temperature to help keep you comfortable.