A production flow base (1) for possible future branched connection onto a production manifold (10) in order to provide for the connection of at least two production jumpers extending from respective subsea Xmas trees onto the production manifold (10), is shown. The production flow base (1) is arranged as a retrofit module connectable to a single inboard hub (11) prearranged on the production manifold (10). The production flow base (1) includes a frame structure (2), piping (3), at least one connector (4) and guiding means (9). The frame structure (2) is arranged for landing on a supporting arrangement (12) projecting from a manifold structure (10). The piping (3) forms a branch terminating in a connector (4) and at least two outboard hubs (6).