These replacement O-ring seals restore a leak-free joint on Prevost PPS1 aluminum flanged fittings. When a joint starts to weep after repeated assembly, swapping the seal is faster and far cheaper than cutting out and replacing the fitting itself.They fit the flanged fittings and valve bodies in the Prevost aluminum air piping system. Match the seal to your tube outside diameter or fitting size using the table below. Available Variants & SKUsAll variants and part numbers for this product are listed below for easy reference and ordering. SKU Description PPS1 GPB50 For 2" tube OD (pack of 4) PPS1 GPB63 For 2 1/2" tube OD (pack of 4) PPS1 GPB80 For 3" tube OD (pack of 4) PPS1 SEAL160 For 6" fitting (qty 1)