The SR5 is the base model but it's not bare-bones. Standard features include cloth upholstery, skid plates, foglights, a backup camera, keyless entry, five 12-volt power outlets and a 120-volt AC power outlet. Stepping up to TRD Off-Road adds some serious off-road chops in the form of a locking rear differential, wheels that are 0.5 inch wider and a crawl control function. It also offers the optional KDSS suspension. Premium variants of the SR5 and TRD Off-Road get power-adjustable and heated outside mirrors, premium vinyl upholstery, navigation and an auto-dimming rearview mirror. Serious off-roaders should consider the TRD Pro, which starts with the TRD Off-Road Premium and adds revised front springs, Bilstein dampers with rear remote reservoirs, Nitto Terra Grappler tires and a front skid plate. Limited models top the 4Runner range. These models get a Torsen center differential (4x4 models only) plus a host of features to make it better suited to on-pavement use: 20-inch wheels, a sunroof, dual-zone climate control, parking alerts, perforated leather seat upholstery, a 15-speaker premium audio system. Power running boards are optional. Key safety features include Vehicle Stability Control, Traction Control, ABS with EBD, Brake Assist, and Smart Stop Technology. It also has eight standard airbags, including front, side, and knee airbags, and roll-sensing side curtain airbags.