Engine Oil Pressure Sensor D1846A for Chevy Silverado GMC Sierra Oil Pressure 12616646 Fits Chevrolet Silverado, Avalanche, Corvette, Express, Impala, SSR, Suburban, Tahoe, Trailblazer. GMC Envoy, Sierra etc. Please see the detailed description to know the exact model and year this item fits. Material:The pressure sensor is made of aluminum.The spacer ring at the bottom of the screw thread is made of oxidized Iron. Can be effective anti-oxidation and anti-corrosion. Direct Replace OE#: 12616646, D1846A Notice: Remember to pull out the weather seal packing from the old unit and put it in the new unit. For easier installation, you may need to purchase an Oil Pressure Switch Socket extra.