Singer Futura 900 Stop Dogs
It should be compatible with most 900 series Futura machines
Support is pre-added; you just need to snap off the 3 blocks after printing and set the layer height to 0.2mm or less.
UPDATE: Model is now 9mm tall instead of 8 due to clipping issue from underneath in machine causing left feed dog to snap off, also added circles to the supports to make them easier to snap off.