Model: 650 (1/4 Turn Round knob with Open/Close Indication Window), Material: S (316L SS Secondary Remelt), Surface Finish: M [10 μin. (0.25 μm)], Ports: 2PW [2 Ports (1-In; 2-Out)], Connection 1: TW4 (1/4 Inch Tube Weld), Connection 2: TW4 (1/4 Inch Tube Weld), Connection 3: No Port, Connection 4: No Port, Face to Face Dimension: 1.75 Inch (44.5mm), Seat Material: PCTFE, Standard, Installation