Sovol SV01 Trays. Probably it is compatible with other Sovol printer but I can't confirm.
In order to install them is very easy just glue them together. Remove one rubber feat and insert them from the bottom. Put rubber feat back and it is done.
For more support in case is needed, can be added a big shim to the middle screw from the bottom cover.
The author marked this model as their own original creation.