This prop shaft or lower crankcase oil seal is a crucial component for your outboard engine. It is specifically designed for Johnson, Evinrude, and OMC models from 1988 to 2001, with a replacement for OMC # 330137. The seal is made by Sierra, a trusted brand in the industry, and comes with a manufacturer part number of 18-2001. The inside diameter of the shaft size is 1.125", while the outside diameter is 1.624", and the width is 0.250". This lower unit component is perfect for those looking for a replacement part for their outboard engine.