This is a Feeder Back-plate for the Wanhao Duplicator i3 Plus so that flexible filament can be printed without the filament escaping through any gaps.
There are two versions,
the first is suitable to use with the stock nozzle setup,
the second is suitable for use with the Swiss Micro hot end Mod, it has a counter bore on the bottom surface to take the top protuberance of the Swiss Micro assembly.
The modified plate has a small web that aligns with the pressure bearing groove preventing the flexible filament escaping via this small gap.
I would recommend printing at 0.1mm layer height with it lying on what is the right end surface as you look at the print head, print with supports, in the material of choice, this area didn't get hot in testing with a plate printed in TwoBears PLAtech.
During assembly align the small curved web with the groove in the pressure bearing.
This is a 'What Duck' design