Fuel system cap for General Motors 3.0 Diesel in 1500 pickups. Protect your vehicle's fuel system from unwanted dirt or water. This is specifically for the Duramax Diesel capless fuel system on the Silverado Sierra 3.0L Duramax Diesel engine. If it doesn't have that specific engine in a Half-ton pickup I cannot guarantee fitment. Made of 3D printed TPU material giving it a tough, reliable fit. Just slide it onto your fuel filler neck and it'll keep all the debris away.