A large number of commercial vessels are manufactured with a multi-bolt flange in lieu of a stern tube. Often, these flanges have a standard bolt pattern. In order to facilitate the installation of the PSS Shaft Seals on boats with these type of flanges, PYI manufactures an array of flanges which fit the "standard" bolt patterns and transform the flange into a stern tube ready to accept the PSS Shaft Seal. These adapters can be ordered as a "standard unit" or as an "inflatable bladder unit". The inflatable bladder option allows the operator to seal the stern tube, while the shaft is not rotating, in order to inspect or clean the seal. In addition, if the uncoupling of the shaft is needed, this operation can be done in the water as the shaft can be moved aft with bladder inflated with no water intrusion occurring. This inflatable bladder can also be used in case of an emergency.