Parts & Accessories Spare parts Sierra - Silverado Catback Model 2007 - 2018 . Two outlets right . Muffler size is 3 inches. . Catback with the device (electronic) 3 inches. . 304 Steel. . Increases engine performance and horsepower. . Compatible with Sierra and Silverado models from 2007-2018. . And it withstands throwing Corsa Copy Offer / 2000 from Shayeef Makkah / Taif