ThunderMax Z309-591 ThunderMax w/AutoTune for Touring 21-UpExhaust Note: On 2010up FLH models, the OEM exhaust system has 12mm o2 ports. The factory 12mm exhaust system is not compatible with the 18mm ThunderMax oxygen sensors. Models with 12mm ports require the purchase an aftermarket exhaust system with 18mm ports. * A 3 Year Limited Warranty covers the Thundermax ECU and the Autotune module against defects in materials or workmanship from the date of purchase by the ORIGINAL consumer for a period of 3