Cap / tip protector for colored pencils
A cap for round pencils. Slide it on and give it a little press, and a tapered ring inside lightly grips the tapered part of the pencil body to keep the cap on. Slots near the end let you see the tip.
I designed this for use on a couple of fabric marking pencils so I could just toss them in a bin with other tools and not have the tips getting broken all the time. It should fit most colored pencils. Writing pencils might bottom out since they're usually sharpened at a narrower angle.