NOS genuine GM ACDelco rear drum brake wheel cylinder.   GM 18019217 / ACDelco 172-1517.  This part is long discontinued. Packaging exhibits shelf wear and staining. Bare metal unpainted surfaces exhibit spots of cosmetic surface oxidation.  Fitment for various Buick, Chevrolet, Oldsmobile, and Pontiac vehicles 1991 thru 2005.  

Check photos for cosmetic concerns before you buy.  Check your VIN with your local GM dealer for correct fitment before you buy.