GMC 4-Inch iStep Running Boards by APS®, 1 Pair. The iStep provides an exceptional appearance enhancement for your vehicle. The innovative patended design, designed after the popular smartphone, gives that unique look and functionality that car enthusiasts are looking for. Secured with a full length non-slip pad, the iStep provides a level of quality you can trust. These solid, one piece iSteps are the ideal side steps for your vehicle.