Due to the Jeep's advanced electronics, simply bolting on larger wheels and tires doesn't cut it anymore. The module is programmed by the adjustment of dipswitches. This is a cool tool for enthusiasts who not only bump up their rig's tire size, but also use different tires for varying four-wheeling conditions. The module recalibrates the Jeep's ECM to function normally with 24- to 53.75-inch-diameter tires. After recalibrating one of our JKs we noticed an improvement in overall performance and handling.