Tool O2 Sensor InstallerCaracteristicas: Adds 18 mm x 1. 5" threaded bungs Complete bung kit includes 1 hydraulic insertion tool, 1 drill bit, 2 O2 sampler blocks, tubing, 25 rivnuts, 25 screws and, 25 copper washers Remove heat shields, install bung and tune; when completed, use included screw and copper washer to seal bung and then replace heat shield for unaltered finish No pump or sampling tube required and allows both cylinders to easily be monitored at the same time