Standard features on the 4Runner SR5 include 17-inch alloy wheels, skid plates, hill-start assist and hill-descent control, heated mirrors, foglights, air-conditioning with rear ventilation, cruise control, full power accessories, a power rear window, a tilt-and-telescoping steering wheel, a trip computer, Bluetooth (with audio streaming) and an eight-speaker sound system with a CD player, satellite radio, an auxiliary audio jack and a USB/iPod interface. The 4Runner Trail level is only available as a 4WD model, and it includes the above equipment plus mud guards, a locking rear differential, Crawl Control (which electronically modulates throttle and brakes when ascending or descending hills), off-road-oriented tires, a sunroof, water-resistant seat fabric, power front seats, a rearview camera with a monitor integrated into the mirror, a sliding rear cargo deck, upgraded gauges and two 120-volt household power outlets. The Limited includes 20-inch wheels, adaptive suspension dampers, keyless ignition/entry, automatic headlights, dual-zone automatic climate control, leather upholstery, heated front seats and power lumbar support for the driver seat. Also standard for the Limited is an integrated rearview camera, HD radio and Toyota's Entune smartphone integration system. Standard 4Runner safety features include antilock disc brakes, stability and traction control, active front head restraints, front knee airbags, front-seat side airbags and full-length, roll-sensing side curtain airbags.