Difficult

Gets rid of bad ones, short and tall. Tightens when used, one size fits all.

related riddles

Green arrows grow out of my sides. I go from yellow to white. My babies fly in the wind. What am I?

My head bobs lazily in the sun. You think I'm cute. For my face is yellow my hair is white and my body is green.

What types of words are these: madam, civic, eye, level?