Here is a panzarella lemon. On the right is an average sized grapefruit. These are really on the small size for the lemon. John said his tree was overloaded this year. I met him today at a farmer's market in Houston. He was selling persimmons and P. lemons. They taste mild like a meyer lemon. I made a quart of lemonade with the one lemon tonight.
You can see this one on my website at least 2x the size of a grapefruit. I picked out the largest one I could find on his tree a couple years ago.