O2 Sensor Port Plug KitPlugs SuperTrapp O2 sensor ports when using exhaust on earlier H-D models that don't require an O2 sensorKit includes two 18 x 1.5mm plugsMade in the U.S.A.Thread Pitch Metric: 1.5 mm Units: Pair Thread Pitch: 1,5 mm Type: O2 Sensor Thread Diameter: 18 mm Product Name: Plug