Extension Tubes.

Here's some visual reasons why I love my Extension Tubes for my old Nikon D60 and why buying them 6 years ago was the best decision ever!

I still keep this Nikon and I'm using it just for shots like this.

I can't imagine more useful tool in my work today than this. Combining them with good studio flashlights helps me to create a totally different quality if it comes to product/macro photography.