2-1/2-12 x 1-5/8-12 Male O-Ring x Female O-Ring Reducer/ExpanderThe 2 1 2 12 x 1 5 8 12 Male O Ring x Female O Ring Reducer Expander is a precision engineered hydraulic fitting designed to transition between different O Ring Boss (ORB) thread sizes. This adapter enables the connection of a larger male ORB thread to a smaller female ORB thread ensuring a leak proof and high pressure resistant seal. Specification Details TYPE O Ring Reducer Expander DESIGN Straight adapter design for a simple and uninterrupted flow