Mid Pin. The BTS Rudder System Mounting Bracket comes with 2 mounting screws (30000015) and 2 washers (3730-0103). A 3/16 inch hex wrench will be needed (17070009). It fits all modern Wilderness Systems kayaks. It is also applicable to the Mad River Synergy. Also fits some Perception kayaks.
Instructions are not included. This plastic rudder gudgeon is common in Wilderness Systems rudder kits made 2010 and later. Screw holes accommodate 5/8 inch spacing. This is more or less the same as the older metal version. (Alternative part number for plastic version is 14820041) ERBA-
Learn more at these links:
Confluence Rudder Install Video part 1 (rudder, lift line, foot braces and control cables)
Confluence Rudder Install Video part 2 (rudder tubes)