The Top Popper allows you to easily open cans of soda. The innovative Top Popper can opener simply slips on the index or middle finger between first and second knuckles and has a comfortable glossy nickel-colored finish. To open, just slide the hook on top of top popper toward you to effortlessly open cans without broken nails. Available in Small, Medium, and Large. The descriptive image shows the diameter of the rings.
In general, if you have small fingers, get a small. If you have large fingers, get a large. Everyone else should be good with a medium. Remember, it only has to go over your first knuckle.