Dimensions of iPhone 11 cases

Why do you need to know the dimensions of the case exactly?

There is only one iPhone 11. Any case that says it works with an iPhone 11, works with the iPhone 11.

The other models are iPhone 11 Pro, and 11 Pro Max.

Unless the case specifically states its for the Pro or Max specifications, its meant for the iPhone 11 and there's only one size of that particular iPhone model.

In general cases would have comparable dimensions to the iPhone they are meant for, maybe a bit larger overall.

Pretty much every case I have ever seen sold specifies the phones it fits.

You can find the sizes for iPhones here:

iPhone - Compare Models - Apple

https://www.apple.com/iphone/compare/

Try going to the website for a particular case. Many of them will provide dimensions there.

Since you're keeping very secret the information about the case then I don't see we can help you more. :-(