Not “no jar” as in I will take your money and not send you anything. “No” Jar as in “This jar says NO on it, and I will mail it to you in the mail.”
At one of my first jobs, my boss had a ceramic trinket on her desk that a student had made, it was a pair of stoneware lips with a big red NO perched on them. It’s important to say YES to yourself, but it’s also really important to say NO!
3.5” wide and 3.5” tall.