Based on https://www.printables.com/model/452840-apple-watch-8-7-41mm-case-perfect-fit-with-step-fi , this case perfectly matches the contours of the watch to create a firm snap-on fit with round borders. Works with any 41mm Apple Watch series 8 and 7.
I also used this to replace my broken OtterBox Case (Like the original creator)
The author remixed this model.