Feuling 18mm Narrow Band 02 Sensor For Harley Feuling oxygen sensors are precision made with gas-permeable platinum electrodes and a porous ceramic to aid the prevention of erosion due to contamination and particulates in the exhaust gases. The ceramic body is made of stabilized zirconium dioxide for long-term durability. Features: Meet or exceed OE specifications 12.5 connector length Replaces OEM 27719-07 Assembled in the U.s.a. Note: Fits Rear only on 2009 Touring / Front and Rear on all other models listed.