When the brake is applied, the programmed flash or strobe pattern will alternate between left and right side lighting accessories creating an eye-catching pattern Compatible with add-on custom LED lighting (such as Custom Dynamics« LED BoltzÖ PN: 2040-2838 & 2040-2839) when used as left and right side rear brake lights 10 selectable flash/strobe patterns Plug and play installation. MODULE BRAKE STROBE 10-13