This 2026 GMC Sierra 2500HD AT4 represents a premium heavy-duty truck built for serious work and commanding presence on any terrain.- Duramax 6.6L V8 Turbodiesel with 10-Speed Automatic and 4WD- AT4 Preferred Package with X31 Off-Road Package- Gooseneck/5th Wheel Prep Package for heavy towing applications- Bose Premium 7-Speaker Sound System with SiriusXM 360L Trial Subscription- HD Surround Vision and Bed View Camera with Trailer Camera Provisions- 2-Speed Active Transfer Case with Hill Descent Control and Off-Road Suspension- Wireless Phone Projection and Apple CarPlay/Android Auto- Heated and Ventilated Front Seats with 10-Way Power Adjusters- Heated Rear Outboard Seats and Heated Steering Wheel- Spray-on Pickup Bedliner with GMC Logo- 20" High Gloss Black 8-Spoke Aluminum Wheels- Remote Vehicle Starter System and Keyless Open and Start- Ultrasonic Front and Rear Park Assist with Rear Cross Traffic Alert- LED Cargo Area Lighting and LED Smoked Amber Roof Marker Lamps- Multiple USB Charging Ports and 120-Volt Power OutletsThe AT4 distinction means this truck comes equipped with specialized off-road capability through its X31 Off-Road Package, which includes an off-road-tuned suspension, 2-Speed Active Transfer Case, and Hill Descent Control. These features work together to provide confidence on challenging terrain while maintaining the comfort and refinement expected in a premium cab.The Duramax diesel engine paired with the 10-Speed Automatic transmission delivers the power needed for demanding work applications. The Gooseneck/5th Wheel Prep Package indicates this truck is ready for serious towing operations, with dedicated provisions built into the frame and bed for maximum capability and safety.Inside the cab, you'll find serious comfort and technology. The Bose audio system combined with SiriusXM keeps you connected during long drives, while the heated and ventilated front seats, along with heated rear outboard seats and steering wheel, provide comfort in any season. The wireless charging pad and multiple USB ports ensure your devices stay powered, and wireless phone projection keeps navigation and communication seamless.The truck features comprehensive camera systems including the Bed View Camera and Trailer Camera Provisions with Trailer Viewing Software, making maneuvering and hitching substantially easier. Ultrasonic Park Assist combined with Rear Cross Traffic Alert and Trailer Side Blind Zone Alert provides confidence during precise movements.The Black exterior with 20" High Gloss Black aluminum wheels conveys the rugged sophistication of the AT4 line. The spray-on bedliner with GMC Logo protects your investment while the LED lighting package modernizes the overall appearance.With fresh oil change completed and ready for delivery, this Sierra 2500HD AT4 awaits a buyer who demands both capability and premium comfort in a heavy-duty truck.