VEHICLE COMPATIBILITY: for GM LS LT Series Engines 1997+ for Chevrolet Camaro 1998-2002,2010-2015 for Chevrolet Silverado 1500 1999-2015 for Chevrolet Suburban 2015 for Chevrolet Tahoe 1999-2015 for Chevrolet Corvette 1997-2004,2006-2012 for Chevrolet Trailblazer 2006-2009 for Pontiac G8 2008-2009 for Pontiac Grand Prix 2007-2008 for Chevrolet Avalanche 1500 2002-2006 for Pontiac GTO 2004-2006 for Pontiac Firebird 1998-2002 PRODUCT INFORMATION: Material: Alloy Steel Color: Black Size 1: 25mm / 0.98" Thread Size: M8x1.25 PERFORMANCE: Direct replacement, easy to use. Made of quality material and reliable construction, durable and reliable in use. Not easy to rust, corrode or peel. Install new Car Exhaust Manifold Bolts, then let the auto parts in it work better. NOTICE: a. This is a non-OEM product, accessory ONLY! b. Please check your car model, and reference our product before purchasing. c. Due to manual measurement, the size deviation is about 1-2 cm.