This is a bracket to allow you to hang your tonal fitness system accessories when not in use. I've mounted them to the bottom of the bench to hang the bar, rope, or handles when not in use. The center hole allows for a #6 or #8 countersunk head.
I originally tried printing this with the flat side down, but there is a plus shape that doesn't bridge well. Printing on the side like in the model and gcode only has short straight bridges over the slot and screw hole. Infill probably doesn't need to be as dense as I specified.
The author hasn't provided the model origin yet.