Water lubricated bearings with metric inner ø - inches outer ø. Brass shell. Rightward involute (R) bearing for lefthand rotation propeller. Leftward involute (L) bearing for righthand rotation propeller. The shaft no longer rotates in a polygonal support, but is supported and guided over its entire circumference, thereby reducing vibrations. The shaft rotation promotes a powerful pumping action in the involuted channels, which leads to a considerably increased fluid velocity in the channel and remarkable cooling, lubricating and cleaning effects.