Canon EF-S 24mm f/2.8 STM 'Pancake' lens
https://www.youtube.com/watch?v=GszKAxnDLsU
I picked up one of these, along with a new Canon DSLR, not so long ago.
It was the lens, actually, that got me back into a DSLR. I had sold my
previous Canon DSLR because I was tired of its bulk and weight. The
"pancake" lens makes taking photos with a "real" camera a delight again.
Not expensive, either.