Flat beans are also known as Romano beans and are meatier, wider and less cylindrical than ordinary green beans.
They are also called Italian beans in some regions and have a crispy fresh and flat character. They can either be steamed or microwaved until they are tender. (source)
Can guinea pigs eat flat beans?
They can nibble them but they cant eat too many of them. Too many may make them unwell, but they will enjoy them if you feed them to your piggies.
For more foods that guinea pigs can and can’t eat, check out our guinea pig food list