I've been harvesting cucumbers lately, always forget to take pictures of them.
This cucumber on the right from the photo below, is my favorite size for using for slicing. They are excellent for making cucumbers and vinegar (cucumbers, vinegar, salt and pepper, pretty self explanatory

).
The thickness of it is about the size of a quarter, maybe a little bigger. They grow so fast, it's hard to catch them at the perfect size!