The higherbro Oxygen O2 Sensor is a high-quality, digital sensor designed for use with 2007-2009 Chevrolet Trailblazer, GMC Envoy, Saab 9-7X, and other select vehicles with 4.2L, 2.9L, and 3.7L engines. This sensor comes in a set of 2 pieces, one for upstream and one for downstream, ensuring optimal performance for your vehicle. The sensor is made of stainless steel, making it durable and resistant to corrosion. It features a flange mount for easy installation and is compatible with both 12V and 24V systems. This product is backed by a one-year quality guarantee, providing you with peace of mind in your purchase. Before buying, please check the vehicle compatibility using the 'Select Your Vehicle' feature at the top of the product link to ensure a proper fit.