This is a battery cover for the Vinca DCLA-0605 caliper. The Vinca DCLA-0805 (notice the different model number) battery cover fits for this model, but comes off almost as easily as the original piece. I've resized it to fit tighter on this model.
Updated 27 Oct 2022: The model has been modified for a better fit with the main body of the caliper. It also is shaped better, following the lines of the caliper body.
Thanks to Jamie Claye for the original model.
The author remixed this model.