Those are a thing. I bought them at Fresh Market - they look like regular lemons, but they're sweet. You can peel and eat them like an orange, or you can juice them and boom! Lemonade. They were $2.99/lb and I used 6 of them to make a glass of lemonade. Needless to say, that was the most expensive drink I've ever had in my whole life and it's unlikely I'll do it again. It's good but not that good.