S&S Off Road Division Power Tune XTO Insert Tuner Kit The Power Tune XTO Insert Kit was designed with a focus on fine-tuning both power and sound. The dealer kit encompasses a range of components - two units each of the 1.375, 1.5, 1.625, 1.75 front plugs with 3.5mm holes, 1.75 rear plugs with 3.5mm holes, 1.875, 2, and 2.25, along with a single 1.75 plug. This diverse set allows the user to fine-tune the exhaust system for optimal sound and power. Features: Tunable inserts allow for easy sound and power adjustment Power and torque tuning Tone and sound adjustment Ease of installing 304 Stainless construction